Fórum Visual C# General

Out of Memory Exception

Thu, 19 Nov 2009 18:14:50 Z

Hi,

my application is having multi-threaded components to compare set of data which is a prolonging process, am getting out of memory exceptions often in some systems.

please give some common strategies to address this item..

how to detect primary key column in dataTable ?

Mon, 30 Nov 2009 11:31:42 Z

Hi
how to detect pk column(s) in dataTable ?
thanks

http://www.codeproject.com/KB/codegen/DatabaseHelper.aspx

RegEx

Fri, 27 Nov 2009 23:31:36 Z

I need to know the regex pattern to find specific numbers..lets say [0-3] which means I want to make sure the string contains, 0 and 1 and 2 and 3. Any help?

c# interop and office versions

Mon, 30 Nov 2009 12:32:40 Z

Hi
I have a C# application that creates and displays an Excel spreadsheet, it was built on a PC with office 2007.

My problem is that when I try and load it onto a PC that has an earlier version of Office I get an error message....

Application requires that assembly Microsoft.vbe.Interop version 12.0 be installed in the Global Assembly Cache first.....

Does this mean my application will only run on PC's with Office2007 or can I load this required assembly onto the target PC?

open command prompt

Sun, 29 Nov 2009 20:15:00 Z

I'm trying to get command prompt to open from a forms application and run a but of code the window should stay open but I will need to close it with a button eventually. The following code doesn't seem to work for me can someone tell me what I am doing wrong?

Process p = new Process();
p.Start("CMD.exe", "echo hi\recho 2\r");

Creating a Shortcut using WshShellClass in C#

Wed, 25 Nov 2009 18:41:06 Z

Hopefully this is a very simple solution..

I am trying to create a function that generates a shortcut to the desktop, and it works.. However.. the path I am trying to use causes the shortcut creator to throw an exception..

			WshShellClass wshShell = new WshShellClass();
			IWshRuntimeLibrary.IWshShortcut shortcut;
			shortcut = (IWshRuntimeLibrary.IWshShortcut)wshShell.CreateShortcut(@Environment.GetEnvironmentVariable("USERPROFILE") + "\\Desktop\\QPS_Punch_Clock.lnk");
			shortcut.TargetPath = "C:\\Program Files\\Internet Explorer\\iexplore.exe -k "+Properties.Settings.Default.URL;
			shortcut.Save();

The error I am getting is very generic: Value does not fall within the expected range.

The TargetPath is the culprit, I am unsure how to proceed. I am trying to generate shortcuts that open IE and Kiosk mode.. with whatever URL was specified. If I remove the Properties.Settings.Default.URL concatenation from the Target Path.. the shortcut is created but is a broken link.. because it is set to

"C:\Program Files\Internet Explorer\iexplore.exe -k "

I can also make a working shortcut using only the URL Property, but it obviously is not opening in kiosk mode..

Does anyone have any ideas?

Thanks!

Getting event handlers (list of delegates) of a WinForm control

Mon, 30 Nov 2009 13:48:27 Z

I do like to get the registered event handlers for a certain event of a WinForm control, e.g. Enter. There are solutions by using reflection e.g. http://blogs.interakting.co.uk/steve/archive/2008/05/19/NET--Hacking-events-and-manipulating-delegates.aspx

So what it basically does, is to retrieve a private field with the same name as the event, e.g. "Enter". This works very well with "my own classes". Via the EventInfo I do get the declaring class (for WinForm components mostly Control).

EventInfo eventInfo = t.GetEvent(eventName, BindingFlags.Instance | BindingFlags.NonPublic)

This also proofs in my case, that there is no typo with the name, since I get eventInfo. However, when then trying to access the private field "Event" on Control, I do not get any FieldInfo returned. Obviously the events are somehow different located as in "my classes".

Did some manage to get the list of delegates for a certain control event?

Searching a byte array for a pattern of bytes

Sun, 04 Jun 2006 20:39:38 Z

I am reading a binary file into a one dimensional byte array. Now I need to search that array for a pattern of bytes.

In other words, this is the equivilent of String.IndexOf()

I want to search the binary array and return the index of the subvalue that I searched for.

For whatever reason, I'm having trouble wrapping my head around this. Can anyone give me an example of how to achieve this?

How to print each node of xml file

Sun, 29 Nov 2009 15:07:51 Z

Hi,

I have xml file in which each node has many child nodes and again each child node has many childs and so on. I need to print each node name and value of xml document. I want to do in c# language. Can any one tell me how to traverse xml file.

Here is example of xml file

<data>
<file>
     <name>gunjan.txt</name>
     <path>c://temp</path>
</file>
<file>
     <name>kajal.txt</name>
     <path>c://temp</path>
</file>
</data>

VS Express - deploying different than ClickOnce?

Mon, 30 Nov 2009 13:34:42 Z

Hi,
I would like to create deployment for my app with the setup but I cannot find Setup project that I could add. The only way seems to be Publish. What am I missing? Thanks

Panel with background Image

Fri, 27 Nov 2009 21:15:23 Z

Hello,

i have a Panel with background picture it shows (only the Click half), and the question is how the show the other half only with a click of an button.

screen resolution

Mon, 30 Nov 2009 09:19:57 Z

i think made a big mistake when i design my GUI.
When i design my GUI, i only care on screen resolution of my working PC. As i port to other PC, i just to saw the problem ... the size of the GUi not same as in my working PC.

Basically, I'd created a Gui in usercontrol; in that control i place two picture boxes side by side which one's width is 1020 and the other is 205. This scales are working good in my working PC (screen resolution = 1280 x 768)

So my question is how do i make those scale fit to any PC ( e.g. 1900 x 1200) ? What suppose should i do? I would like all the design scale to fit with 1900 x 1200.
Should i use Dock properties? I cant find dock properties in usercontrol.

Please Guide.
Thanks.

draw consecutive polygon

Mon, 30 Nov 2009 07:02:53 Z

Hi,

I want to draw consecutive polygon of similar side inside a given polygon (of any number of sides-regular or irregular polygon) at a specified distance (varies).

When the space inside the polygon is not enough to draw another polygon, I should stop drawing polygon.

Can anyone tell me how to detect whether the a polygon at specified distance can be drawn inside the polygon or not.

Thank you

M Rajee

Why there is app.config file if its only for reading?

Mon, 30 Nov 2009 09:23:51 Z

Hi,
I do not understand why there has to be app.config file in the release directory, because when setting is changes it is being saved to appdata directory relatively to Win user. If its only for reading, why its not embedded in the app? I have tried to embed it and released app works, but debugging doesnt (ConfigurationErrorException). I am trying to have as less files as possible.
Thanks

Method Name Expected Compile Error - Windows Service Timer Project

Sun, 29 Nov 2009 17:29:00 Z

I have a Window Service project that has a timer. I have a line of code in the Timer Event that kicks off a method. However, I am having trouble passing through my parameters in this line. I am getting a compile error that reads "Method Name Expected". Any thoughts?

_timer.Elapsed +=

new System.Timers.ElapsedEventHandler(MoveFiles(@"C:\temp",@"C:\temp","*.txt"));

My method called MoveFiles is defined as follows;

public static void MoveFiles(string sourceDir, string destinationDir, string pattern)

{

var fileQuery = from f in Directory.GetFiles(sourceDir, pattern)

select new {Source = f,Destination = Path.Combine(destinationDir, Path.GetFileName(f))};

fileQuery.ToList().ForEach(f =>

File.Move(f.Source, f.Destination));

}

Any help is appreciated!

Thanks,
Ryan

dataviewgrid - binding keeps adding more columns

Sun, 29 Nov 2009 22:29:13 Z

I created a dataview grid in the designer to layout my UI.
I leave it empty until I am ready to display data to the user. I wanted the user to see the control and the column headings from the start though.
So, I defiend the columns of the grid in the designer.

Now while my application is running the user clicks a button, I handle the event:
Create a dataset, create its tables, fill the tables, bind the grid to one of the tables.

My problem is that whenever I go through the steps to bind the grid to my new table
1) It adds all the columns from the new table to its already defined columns, doubling its number of columns.
2) It uses the DataColumn.ColumnName property insead of the DataColumn.Caption property that I would expect.

My steps are simply:

//...grid is already shown and has column names from form init time
grid.DataSource = null;
CreatesMyDataSet();
m_myDataSet.Tables["myTable"] ;

How can I solve those problems?

I'm having trouble clicking on an automatically alert (javascript) using a WebBrowser component in C#.

Tue, 24 Nov 2009 12:28:30 Z

Hello,
I'm using a component (WebBrowser) to open a URL from third parties and do some actions, such as automatically populate fields in a form and click the submit button also automatically.
The problem is that the page that I access has changed and every time she opens a wheel javascript onload in BODY tag with an alert that blocks the continuation of my process of completing and submitting the form automatically.
You can click on an alert automatically or simulate the "ENTER" button for confirmation?

PS: This is a desktop application made in C # with NET 3.5 framwork

How can I select the current paragraph in a richtextbox?

Mon, 30 Nov 2009 02:51:57 Z

My question is the same as the one in this thread http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/df8de69f-0ae6-44f6-8c79-57bc4327d519. I tried to use the answer chosen there, but could not get it to work. I replied on that thread to try to get some more help but it already had an answer marked so no one responded.

Open-Closed Principle in C#

Tue, 24 Nov 2009 20:39:56 Z

Hi I would like to illustrate the Open-Closed Principle. I'm asking my self about how to use C1 and C2 methods in A withouth modifing the class A.

Thanks.

Here is my code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OuvertureFermeture
{
    interface I { void sub_foo(); void sub_bar(); }
    class C1 : I
    {
        #region I Membres

        public void sub_foo()
        {
            Console.WriteLine("sub_foo : C1");
        }

        public void sub_bar()
        {
            Console.WriteLine("sub_bar : C1");
        }

        #endregion
    }

    class C2 : I
    {
        #region I Membres

        public void sub_foo()
        {
            Console.WriteLine("sub_foo : C2");
        }

        public void sub_bar()
        {
            Console.WriteLine("sub_bar : C1");
        }

        #endregion
    }


    class A 
    {
        private I _C { get; set; }
        public void foo() { _C.sub_foo(); }
        public void bar() { _C.sub_bar(); }
        public A() { }
    }
    class Program
    {
        static void Main(string[] args)
        {
            //A a = new A();
            //a.foo();
            //a.bar();
        }
    }
}

COM Interop - switching to STA Threading - how to?

Fri, 27 Nov 2009 19:17:51 Z

Hi

I am working on a web service whose business layer has a hybrid of COM and .Net business objects. I can get the data from the .net business objects fine. I have tests which prove that the COM business objects work fine when accessing them from VS2008's test suite. However, when I try and access them via the web service, an error is generated. (Exception from HResult: 0x800A0062). I managed to replicate this problem using various testing scenarios and got rid of the problem by explicitly setting the threading to STA.

So I figured that, when invoking any of my COM methods, I first need to switch to an STA Thread.

I am struggling to know how to do this. I have tried 2 methods.

a) Getting hold of the current thread and setting its apartment state to STA, but that generates an error on the development server
b) Explicitly trying to create a new STA thread. Here's my code ... but be warned I'm a threading newbie!

public class STATaskExecutor
    {

        static Thread _thread;
        static MyCOMDLL.CFactory _factory;
        static MyCOMDLLTypes.IMyCOMType _myCOMObject;
        static string _var1;
        static string _var2;
        static string _var3;
        static bool _created;

        public static MyCOMDLLTypes.IMyCOMType CreateCOMObject(MyCOMDLL.CFactory p_factory, string p_param1, string p_param2, string p_param3)
        {
            _factory = p_factory;
            _var1 = p_param1;
            _var2 = p_param2;
            _var3 = p_param3;

            _thread = new Thread(CreateCOMObjectInstance);
            _thread.SetApartmentState(ApartmentState.STA);
            _thread.Start();

            while (!_created){ }

            return _COMObject;
        }

        [STAThread]
        private static void CreateCOMObjectInstance()
        {
            try
            {
                _COMObject = _factory.CreateIMyInterface(_var1, _var2, _var3;
            }
            catch (Exception ex)
            {

            }
            finally
            {
                _created = true;
                _thread = null;
            }
        }

I am finding that the CreateCOMObjectInstance executes, but it is failing with the same error.

a) Could it be failing for some other reason?
b) Where am I going wrong in relation to the implementation of creating an new STA thread
(finally but non-essentially since it doesn't work)
c) Is there a more elegant ways of passing around the COM function (e.g. as a first class function). I don't know if you can pass round COM methods as first class functions!

Many thanks

Simon

Delegates and References to classes

Sat, 28 Nov 2009 18:39:12 Z

Hi

If I have the following code:

class
 A
{    

     public
 A(Action<int
> myDelegate)
     {
         MyDelegate = myDelegate;
     }
 
    Action<int
> MyDelegate {get
; private
 set
;}
}


class
 B
{   

  public
 B(Action<int
> myDelegate)
     {
         MyDelegate = myDelegate;
     }
 
    Action<int
> MyDelegate {get
; private
 set
;}
}

If I do:

 Action<int
> action = i => DoSomething(i);

 A = new

 A(action);
 B = new

 B(A.MyDelegate);

Will the class B be created with the reference to the underlying delegate or will it keep a reference to class A? As if it keeps a reference to class A and I want class A to be garbage collected it could create a memory leak as long as B is alive.

Thank you

Active Directory Password Stop List

Fri, 27 Nov 2009 11:43:18 Z

I need to write a custom password filter for AD that will read a list of stop words from something like a file or a registry entry.

My skills are really in .NET and in particular in C# but all the examples I've seen are in C++ obviously and are around RegEx rather than stop words.

Does anyone have a basic .NET one that I can take and play with that presumably gets wrapped in a CCW or something?

Thanks,

Martin

Rejecting incomming call in c#

Mon, 30 Nov 2009 05:26:23 Z

Hi, I am developing a windows mobile application in c# where i need to reject the incoming call on some condition is there any way for rejecting the incoming call.can i get some pointers regarding this.

Thanks in advance.

Determine direction of specified point

Mon, 30 Nov 2009 10:22:40 Z

Hi,
I want to produce a a compensating equivalent of a continuous poly-line at specified distance apart the given poly-line in the specified direction of the point given. Poly-line can be drawn as they like and can take any shape, closed or open.

I just what to determine whether the specified point is on which side. Refer the link below for Pictorial view

http://www.kodakgallery.com/gallery/creativeapps/slideShow/Main.jsp?token=146826487113%3A1204117644&cm_mmc=site_email-_-new_site_share-_-core-_-View_photos_link

Otherwise is there any other approach to do so? Provide Sample.

Thank You
M Rajee

how to check the checkbox column in WPF datagrid ??

Mon, 30 Nov 2009 10:19:44 Z

hi all ,

i hav added the one column in WPF datagrid as checkbox.

i wann to know that hw can i check the each row in datagrid is checked or not ??

thx in advance

Video compression driver not responding to SendMessage() function

Thu, 19 Nov 2009 16:44:20 Z

Hi,

I'm trying to connect my C# program to a webcam.

I've done everything necessary to connect to my webcam and everything is working fine - I am able to retrieve video data from the webcam, but it's compressed, so I need to use the proper video compression driver to decompress it into RGB.

And here begins my problem:

I'm using the ICOpen() function from msvfw32.dll to find the driver I need. It returns a non-zero handle to a driver. But whenever I try to send a message to it, it just returns 0 and does nothing with the passed parameters (e.g. with messages like ICM_GETINFO or ICM_DECOMPRESS_GET_FORMAT).

I don't know what I'm doing wrong - I've seen some other C# and VB programs that do it the same way and they didn't experience such problem.

I've been trying also the ICLocate() function but with the same result. Maybe the problem is the driver. I don't know :-(

By the way, the compression that uses my webcam is YUY2.

Here is the source code (The problem is in the Capture.Device.Connect() method):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Drawing;

namespace Capture
{ 
    public delegate void FrameCallback(Bitmap bmp);
    public class Device
    {
        #region Structures
        [StructLayout(LayoutKind.Sequential)]
        struct ICINFO
        {
            int dwSize;
            int fccType;
            int fccHandler;
            int dwFlags;
            int dwVersion;
            int dwVersionICM;
            unsafe fixed char name[16];
            unsafe fixed char desc[256];
            unsafe fixed char driver[256];
        }
        [StructLayout(LayoutKind.Sequential)]
        struct BITMAPINFO
        {
            public int biSize;
            public int biWidth;
            public int biHeight;
            public short biPlanes;
            public short biBitCount;
            public int biCompression;
            public int biSizeImage;
            public int biXPelsPerMeter;
            public int biYPelsPerMeter;
            public int biClrUsed;
            public int biClrImportant;

            public static BITMAPINFO Default
            {
                get
                {
                    BITMAPINFO bi = new BITMAPINFO();
                    bi.biSize = 40;
                    bi.biPlanes = 1;
                    bi.biBitCount = 24;
                    return bi;
                }
            }
            //public int[] ColorTable;
        }
        [StructLayout(LayoutKind.Sequential)]
        struct VIDEOHDR
        {
            public IntPtr lpData;           // Pointer to locked data buffer
            public uint dwBufferLength;     // Length of data buffer
            public uint dwBytesUsed;        // Bytes actually used
            public uint dwTimeCaptured;     // Milliseconds from start of stream
            public uint dwUser;             // For client's use
            public uint dwFlags;            // Assorted flags (see defines)
            [MarshalAs(UnmanagedType.SafeArray)]
            byte[] dwReserved;              // Reserved for driver
        }
        [StructLayout(LayoutKind.Sequential)]
        struct CAPSTATE
        {
            public uint uiImageWidth;
            public uint uiImageHeight;
            public int fLiveWindow;
            public int fOverlayWindow;
            public int fScale;
            public int ptScrollx;
            public int ptScrolly;
            public int fUsingDefaultPalette;
            public int fAudioHardware;
            public int fCapFileExists;
            public int dwCurrentVideoFrame;
            public int dwCurrentVideoFramesDropped;
            public int dwCurrentWaveSamples;
            public int dwCurrentTimeElapsedMS;
            public IntPtr hPalCurrent;
            public int fCapturingNow;
            public int dwReturn;
            public uint wNumVideoAllocated;
            public uint wNumAudioAllocated;
        }
        #endregion

        delegate void CallbackGetFrame(IntPtr hwnd, ref VIDEOHDR videoHeader);

        #region Constants
        const int GWL_EXSTYLE = -20;
        const int GWL_STYLE = -16;
        const int GWL_WNDPROC = -4;
        const int GWL_HINSTANCE = -6;
        const int GWL_HWNDPARENT = -8;
        const int GWL_ID = -12;
        const int GWL_USERDATA = -21;
        const int DWL_DLGPROC = 4;
        const int DWL_MSGRESULT = 0;
        const int DWL_USER = 8;

        const short WM_CAP = 0x400;

        const int WM_CAP_SET_CALLBACK_FRAME = WM_CAP + 5;
        const int WM_CAP_DRIVER_CONNECT = WM_CAP + 10;
        const int WM_CAP_DRIVER_DISCONNECT = WM_CAP + 11;
        const int WM_CAP_EDIT_COPY = WM_CAP + 30;

        const int WM_CAP_GET_VIDEOFORMAT = WM_CAP + 44;
        const int WM_CAP_SET_VIDEOFORMAT = WM_CAP + 45;
        const int WM_CAP_SET_PREVIEW = WM_CAP + 50;
        const int WM_CAP_SET_PREVIEWRATE = WM_CAP + 52;
        const int WM_CAP_SET_SCALE = WM_CAP + 53;
        const int WM_CAP_GET_STATUS = WM_CAP + 54;
        const int WM_CAP_GRAB_FRAME = WM_CAP + 60;
        const int WS_CHILD = 0x40000000;
        const int WS_VISIBLE = 0x10000000;
        const short SWP_NOMOVE = 0x2;
        const short SWP_NOSIZE = 1;
        const short SWP_NOZORDER = 0x4;
        const short SWP_FRAMECHANGED = 0x20;
        const short HWND_BOTTOM = 1;

        const int ICTYPE_VIDEO = (int)'v' | (int)'i' << 8 | (int)'d' << 16 | (int)'c' << 24;
        const int ICMODE_DECOMPRESS = 2;
        const int ICMODE_FASTDECOMPRESS = 3;
        const int ICMODE_FASTCOMPRESS = 5;
        const int ICMODE_DRAW = 8;
        const int ICM_GETINFO = 0x4000 + 0x1000 + 2;
        const int ICM_DECOMPRESS_GET_FORMAT = 0x4000 + 10;
        const int ICM_DECOMPRESS_BEGIN = 0x4000 + 12;
        const int ICM_DECOMPRESS = 0x4000 + 13;
        const int ICM_DECOMPRESS_END = 0x4000 + 14;
        #endregion

        #region PInvokes
        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        static extern bool SetWindowPos(IntPtr hwnd, IntPtr hWndInsertAfter, int x, int y, int cx, int cy, uint wFlags);

        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        static extern int SetWindowLong(IntPtr hwnd, int type, int value);

        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        static extern int GetWindowLong(IntPtr hwnd, int type);

        [DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        static extern bool DestroyWindow(IntPtr hwnd);

        [DllImport("avicap32.dll", EntryPoint = "capCreateCaptureWindowW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr capCreateCaptureWindow(string lpszWindowName, int dwStyle, int x, int y, int nWidth, short nHeight, IntPtr hWndParent, int nID);

        [DllImport("avicap32.dll", EntryPoint = "capGetDriverDescriptionW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern bool capGetDriverDescription(short wDriver, string lpszName, int cbName, string lpszVer, int cbVer);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, [MarshalAs(UnmanagedType.AsAny)]object lParam);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, ref BITMAPINFO lParam);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, CallbackGetFrame callback);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, ref CAPSTATE state);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, ref BITMAPINFO bIn, ref BITMAPINFO bOut);

        [DllImport("user32", EntryPoint = "SendMessageW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern int SendMessage(IntPtr hwnd, int wMsg, ref ICINFO bIn, int size);

        [DllImport("user32", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr SetParent(IntPtr child, IntPtr parent);

        [DllImport("user32", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr GetParent(IntPtr child);

        [DllImport("msvfw32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr ICLocate(int type, int handler, ref BITMAPINFO biIn, ref BITMAPINFO biOut, short flags);

        [DllImport("msvfw32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr ICLocate(int type, int handler, ref BITMAPINFO biIn, int lpBiOut, short flags);

        [DllImport("msvfw32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
        static extern IntPtr ICOpen(int type, int handler, uint flags);

        [DllImport("msvfw32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
        static extern int ICDecompress(IntPtr dec, uint flags, ref BITMAPINFO biIn, IntPtr source, ref BITMAPINFO biOut, IntPtr target);
        #endregion

        string name;
        string ver;
        int id;
        IntPtr capWnd = IntPtr.Zero;
        bool conn = false;
        BITMAPINFO binfo;
        BITMAPINFO biOut;
        IntPtr dec = IntPtr.Zero;

        Device(int i, string n, string v)
        {
            id = i;
            name = n;
            ver = v;
        }
        ~Device()
        {
            if (capWnd != IntPtr.Zero)
            {
                Disconnect();
            }
        }
        void FrameCallback(IntPtr hWnd, ref VIDEOHDR vhdr)
        {
            if (hWnd == IntPtr.Zero) return;
            IntPtr data = vhdr.lpData;
            //if (binfo.biCompression != 0)
            //{
            //    data = Marshal.AllocHGlobal(biOut.biSizeImage);
            //    if (ICDecompress(dec, 0x80000000, ref binfo, vhdr.lpData, ref biOut, data) != 0) return;
            //}
            Bitmap bmp = new Bitmap(Width, Height, Width*binfo.biBitCount/8, System.Drawing.Imaging.PixelFormat.Format24bppRgb, data);
            Callback(bmp);
        }

        public bool Connect()
        {
            capWnd = capCreateCaptureWindow("", 0, 0, 0, 0, 0, IntPtr.Zero, id);
            if (0 == SendMessage(capWnd, WM_CAP_DRIVER_CONNECT, id, 0))
            {
                DestroyWindow(capWnd);
                return false;
            }
            binfo = BITMAPINFO.Default;
            binfo.biWidth = 640;
            binfo.biHeight = 480;
            binfo.biSizeImage = binfo.biBitCount * binfo.biWidth * binfo.biHeight / 8;
            //if(SendMessage(capWnd, WM_CAP_SET_VIDEOFORMAT, 40, ref binfo) == 0) return false; // the webcam doesn't accept the new format
            SendMessage(capWnd, WM_CAP_GET_VIDEOFORMAT, 40, ref binfo);
            if (binfo.biCompression != 0)
            {
                //biOut = BITMAPINFO.Default;
                //biOut.biWidth = binfo.biWidth;
                //biOut.biHeight = binfo.biHeight;
                //biOut.biSizeImage = biOut.biBitCount * binfo.biWidth * binfo.biHeight / 8;
                biOut = new BITMAPINFO();
                //dec = ICLocate(ICTYPE_VIDEO, binfo.biCompression, ref binfo, 0, ICMODE_DECOMPRESS);
                dec = ICOpen(ICTYPE_VIDEO, binfo.biCompression, ICMODE_DECOMPRESS);
                if (dec == IntPtr.Zero) return false;
                if (SendMessage(dec, ICM_DECOMPRESS_GET_FORMAT, ref binfo, ref biOut) != 0) // should return ICERR_OK that is actually 0
                    return false; // nothing is written in "biOut"
                ICINFO cinf = new ICINFO();
                int s = SendMessage(dec, ICM_GETINFO, 0, 0); // shoul return size of the data but returns 0
                SendMessage(dec, ICM_GETINFO, ref cinf, 296); // after this "cinf" is still empty
                if (SendMessage(dec, ICM_DECOMPRESS_BEGIN, ref binfo, ref biOut) != 0) return false;
            }
            SendMessage(capWnd, WM_CAP_SET_PREVIEW, 0, 0);
            SendMessage(capWnd, WM_CAP_SET_CALLBACK_FRAME, 0, FrameCallback);
            conn = true;
            return true;
        }
        public void Disconnect()
        {
            SendMessage(capWnd, WM_CAP_DRIVER_DISCONNECT, id, 0);
            SendMessage(dec, ICM_DECOMPRESS_END, 0, 0);
            dec = IntPtr.Zero;
            DestroyWindow(capWnd);
            capWnd = IntPtr.Zero;
            conn = false;
            binfo = new BITMAPINFO();
        }
        public void GrabFrame()
        {
            SendMessage(capWnd, WM_CAP_GRAB_FRAME, 0, 0);
        }

        public static Device[] DeviceList
        {
            get
            {
                List<Device> list = new List<Device>();
                string name = new string(' ', 100);
                string ver = new string(' ', 100);
                for (short i = 0; capGetDriverDescription(i, name, 100, ver, 100); i++)
                {
                    list.Add(new Device(i, name.Trim(), ver.Trim()));
                }
                return list.ToArray();
            }
        }
        #region Properties
        public string Name
        {
            get
            {
                return name;
            }
        }
        public string Version
        {
            get
            {
                return ver;
            }
        }
        public int ID
        {
            get
            {
                return id;
            }
        }
        public bool IsConnected
        {
            get
            {
                return conn;
            }
        }
        public IntPtr Handle
        {
            get
            {
                return capWnd;
            }
        }
        public FrameCallback Callback;
        public int Width
        {
            get
            {
                return binfo.biWidth;
            }
        }
        public int Height
        {
            get
            {
                return binfo.biHeight;
            }
        }
        public IntPtr PreviewParent
        {
            get
            {
                if (capWnd == IntPtr.Zero) return IntPtr.Zero;
                return GetParent(capWnd);
            }
            set
            {
                if (capWnd == IntPtr.Zero) return;
                if (SetParent(capWnd, value) == IntPtr.Zero || value == IntPtr.Zero)
                {
                    SetWindowPos(capWnd, new IntPtr(HWND_BOTTOM), 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOZORDER | SWP_FRAMECHANGED);
                }
            }
        }
        public bool Preview
        {
            get
            {
                CAPSTATE cs = new CAPSTATE();
                if (SendMessage(capWnd, WM_CAP_GET_STATUS, 76, cs) == 0) return false;
                else return cs.fLiveWindow != 0;
            }
            set
            {
                SendMessage(capWnd, WM_CAP_SET_PREVIEW, value ? 1 : 0, 0);
                if (value) PreviewRate = 66;
            }
        }
        public int PreviewRate
        {
            set
            {
                SendMessage(capWnd, WM_CAP_SET_PREVIEWRATE, value, 0);
            }
        }
        #endregion
    }
}

Could anybody help me?

Thanks.

WebBrowser

Mon, 30 Nov 2009 10:16:32 Z

Hi to everyone,

When I use WebBrowser control'method public void Navigate(string urlString, string targetFrameName, byte[] postData, string additionalHeaders);

it always takes more and more memory.

I'm calling it in timely manner, every minute.

Is it possible to avoid memory leak?

Seems like it keeps all data and doesn't release it after navigation.

I tried calling GC without success.

Any idea, please?

C# - How to make a Button with a DropDown Menu?

Thu, 26 Nov 2009 10:28:23 Z

I would like to have a Button with a drop down menu and then when I click on the "menu item", I will do something.

However, I have no idea how I can "trigger" the even created by Menu Item, I can only do this, as below...

        private void button1_Click(object sender, EventArgs e)
        {
            ContextMenu cm = new ContextMenu();
            cm.MenuItems.Add("menuItem 1");
            cm.MenuItems.Add("menuItem 2");

cm.Show(button1, new Point(0, button1.Height));
}

So, may I know how I can do this? Please help

Dir list box...

Wed, 25 Nov 2009 18:04:43 Z

Hello every body, i have a dir list box in my form and i give it as path a network path, when i run the form it lists me the contents of the path correctly. i want to know if i can hide from dir list box the base path or if i can rename it, i don't want to see \\server\share i want to see the work "base path" for example !

Do someone know how to auto-filter SEARCH from my datagridview using mysql connections?

Mon, 30 Nov 2009 06:42:36 Z

kindly help me again sir. :) Thanks

how to connect mysql remote database to my c# application?

Mon, 30 Nov 2009 08:55:28 Z

how to connect mysql remote database to my c# application?

connectionstrings.com does not have code for this.

A socket is disposed of in a Timeout and I get an error in ReceiveCallBack() trying to access..

Mon, 23 Nov 2009 21:55:26 Z

Hightlighted in large purple font below are the two lines where the following errors occur and this order;
1. int bytesRead = client.EndReceive(ar); in ReceiveCallBack() and
2. client.Shutdown(SocketShutdown.Both); in DeviceCommunicationTimeOut

I can see that the TimeOut, after 125 milliseconds, is closing the socket and then when there is an unsuccessful attempt to access the socket in the ReceiveCallBack(). But I haven't figured out how to prevent that. Thank you so much for any help on my first asynchronous socket app.

public class StateObject

    {

        public Socket workSocket = null;

        public const int BufferSizeForReceive = 2400;

        public byte[] buffer = new byte[BufferSizeForReceive];

        public StringBuilder sb = new StringBuilder();

        private static byte[] toSocket;

    }

    public partial class Form1 : Form

    {

        private static System.Threading.Timer timerForTimeOut = null;  //one shot 

        private static Object syncObj = new Object();  //Lock when receiving data or TimeOut called



        private static ManualResetEvent connectDone = new ManualResetEvent(false); //??

        private static ManualResetEvent receiveDone = new ManualResetEvent(false); //??

        private static ManualResetEvent sendDone = new ManualResetEvent(false);    //??



        private static byte[] toSocket;

        private static string response;

        private static string softwareVersionFromDevice;

        private static string host = "10.0.110.35";

        private static Int32 port = 50000;

        public Form1()

        {

            InitializeComponent();

            toSocket = new byte[7];

            toSocket[0] = 2; //msgID

            toSocket[1] = 0; //status

            toSocket[2] = 0; //data lehgth

            toSocket[3] = 0;

            toSocket[4] = 0; //seq #

            toSocket[5] = 1;

        }



        private void button1_Click(object sender, EventArgs e)

        {

            BeginConnect(host, port);

        }

        public static void BeginConnect(string host, int port)

        {

            try

            {

                Socket s = new Socket(AddressFamily.InterNetwork,

                    SocketType.Stream,

                    ProtocolType.Tcp);

                connectDone.Reset();

                s.BeginConnect(host, port, new AsyncCallback(ConnectCallback), s);

                connectDone.WaitOne();

            }

            catch (Exception ex)

            {

                Console.Write("BeginConnect exception = " + ex.ToString());

            }

        }



        public static void ConnectCallback(IAsyncResult ar)

        {

            try

            {

                Socket client = (Socket)ar.AsyncState;

                client.EndConnect(ar);

                connectDone.Set();

                // create a one-shot timer

                if (timerForTimeOut == null)

                    timerForTimeOut = new System.Threading.Timer(DeviceCommunicationTimeOut, client, 125, 125);

                Send(client);

            }

            catch (Exception ex)

            {

                Console.Write("ConnectCallback exception = " + ex.ToString());

            }

        }

        private static void DeviceCommunicationTimeOut(object state)

        {

            try

            {

                Socket client = (Socket)state;



                lock (syncObj)

                {

                    // timed out. close and shutdown socket

                    client.Shutdown(SocketShutdown.Both); 

                    client.Close();

                }



            }

            catch (Exception ex)

            {

                Console.Write("DeviceCommunicationTimeOut exception = " + ex.ToString());

            }

        }



        private static void Send(Socket client)

        {

            try

            {

                client.BeginSend(toSocket, 0, toSocket.Length, SocketFlags.None,

                new AsyncCallback(SendCallback), client);

            }

            catch (Exception ex)

            {

                Console.Write("Send exception = " + ex.ToString());

            }

        }



        private static void SendCallback(IAsyncResult ar)

        {

            Socket client = (Socket)ar.AsyncState;

            int bytesSent = client.EndSend(ar);

            sendDone.Set();

            Receive(client);

        }



        private static void Receive(Socket client)

        {

            try

            {

                StateObject state = new StateObject();

                state.workSocket = client;

                client.BeginReceive(state.buffer, 0, StateObject.BufferSizeForReceive, 0,

                new AsyncCallback(ReceiveCallback), state);

            }

            catch (Exception ex)

            {

                Console.Write("Receive exception = " + ex.ToString());

            }

        }



        private static void ReceiveCallback(IAsyncResult ar)

        {

           try

           {

              lock (syncObj)

              {

                 timerForTimeOut.Change(125, 10000);    // Timeout.Infinite

              }

              StateObject state = (StateObject)ar.AsyncState;

              Socket client = state.workSocket;

              int     bytesRead = client.EndReceive(ar); 

              if (bytesRead > 0)

              {

                    state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                    client.BeginReceive(state.buffer, 0, StateObject.BufferSizeForReceive, 0,

                    new AsyncCallback(ReceiveCallback), state);

              }

              else

              {

                 if (state.sb.Length > 1)

                 {

                    response = state.sb.ToString();

                 }

                 receiveDone.Set();

              }

           }

           catch (ObjectDisposedException ex)

           {

              Console.WriteLine("EndReceive exception = " + ex.ToString());

           }

  

        }

    }

Code for a Class file in C#

Mon, 30 Nov 2009 08:31:17 Z

Can anyone help me plz
I want a complete sample of class file through which we can establish an SQL Connection and which include certain important method which is reusable.(Like dataset,datatable,insert etc)..
I mean a common class file for my entire application.
It is for Windows application ,c# and SQL Server2000.
If any one share the code ,it will be very helpfull
Plz reply
Iam waiting
Its urgent
Thanks a lot

http://dotnetsourcecodes.blogspot.com/

Regex for ASCII with exceptions

Fri, 27 Nov 2009 11:03:17 Z

Hi All,

I have been trying to find the correct REGEX expression, but in vain. Hope the experts here can help me further..

I have a string which must be either visible ASCII characters (from 0x20 to 0x7E), but may contain a 0x00.

I tried something on the lines of:

Regex rx = new Regex("[:print:]|\x00");
if (rx.IsMatch(myASCIIString))
{
    //Show
}

But it doesnt work! Any suggestions??

Examples of my string can be:

1E3132 7F - should fail, it has non-visisble ASCII like 0x1D and 0x7F
342033 00 - should pass, has ASCII and also 0x00.
32314145 - should pass, it has only visible ASCII!

Thank u all!!

If the reply answers your question, please mark it as Answer, or Helpful, if it helped! Thanks!

how to atart with c#

Sat, 28 Nov 2009 12:35:16 Z

how to write code in c#

Some help on a threading model, I am using a timer but it does not work, somewhat a newbie question

Mon, 30 Nov 2009 07:01:22 Z

Hi.

I am moving part of a software I have on other languages to C#, basically I am working with a HID device ( I can open it, read it, see if it's attached, set features etc )

but I have a small problem, since I am not that well aquainted with C# I am using a timer:

Timer tmr = new Timer();

tmr.Tick += new EventHandler(tmr_Tick);

tmr.Interval = 50;

Then inside the timer I am reading the HID device, the problem is that I need somewhat realtime

information from the device, but with the timer it just stalls and stall, actually if I set it to 50ms.

the application "dies" waiting for the information.

I know I have to make a thread to read the data, but I am quite confused on what type of thread to use.

I don't mind if for instance a "sample" gets lost, but I need to read the information well as I said before in realtime.

so right now I have a function:

void tmr_Tick(object sender, EventArgs e)

{

readbuffer = readHID();

/** more code after this **/

}

ReadHid is:

public byte[] readHid()

{

///// Some code ////////

///core:

success = FileIO.ReadFile(readHandle, bufferPtr, bufferLength, ref bytesRead, IntPtr.Zero);

Marshal.Copy(bufferPtr, readbuffer, 0, bytesRead);

Marshal.FreeHGlobal(bufferPtr);

return readbuffer;

}

so it returns the byte[] filled with data and then I process the data.

but this kills the program excecution.

can someone help me with this... silly thing. :/

Thank you in advance

Using using System.Runtime.InteropServices.ProgIdAttribute

Mon, 30 Nov 2009 04:28:58 Z

I have a class decorated with:

[

ProgId("Category.Class1")]

But when I do:

Type t = Type.GetTypeFromProgID("Category.Class1")

I get null for t. What am I missing here?
TIA.

two different values to imagecolumn in gridview

Mon, 30 Nov 2009 08:03:41 Z

I have a gridview with an imagecolumn. This column should be able to take two different values from a plc.

One bool value, where the value 0 or 1 should return an image.

One dint value, where the value should actually be shown in the gridview.

How can this be accomplished taken into account that a dint value can also be 0 and 1. I must be able to check on the type bool or dint. Hope anybody can help.

Collection of another collection

Mon, 30 Nov 2009 03:24:14 Z

I need to create a List<KeyValuePair<int,int>> collection. But Fxcop thinks that containing a collection inside another collection is not a good practice.However, defining a class for the KeyValuePair<int,int> sounds strange as well. Doyou have any suggestion about this structure?

Base64 and Byte Conversion

Sat, 28 Nov 2009 02:11:44 Z

Hello,

I have the following:
String result = Convert.ToBase64String(Encoding.UTF8.GetBytes("Test"));

Shouldn't result become "Test"? I get "VGVzdA=="

I am using this approach to save Byte data into a XML file and get it back to a string.
It isn't working so I made this test and I was expecting to get "Test" in result.

Thanks,
Miguel