Open Process in Minimized State

Question

Hello,

I'm trying to open a process (*note that I say process, I'm unable to find the programs titlebar title*) in a minimized state; this is what I've got:

    Private Const SW_HIDE = 0
    Private Sub Form648_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Process.Start("C:\Program Files\Random\Randoms.exe")
        Dim ClientProcess As Process = Process.GetProcessesByName("RandomSLtF").FirstOrDefault
        If ClientProcess IsNot Nothing Then

            SendMessage(ClientProcess.MainWindowHandle, SW_HIDE = 0)


        End If

    End Sub

Although this doesn't send an error, it doesn't work either.

If it matters, the window that I'm trying to open in a minimized state is top-most and has no titlebar (which means no manual minimize option)

Thanks for any help!

Answer 1

Sending SW_HIDE has no sense...

For example with Notepad :

Dim pr As Process = pr.Start(New ProcessStartInfo("notepad"))
pr.WaitForInputIdle()
Dim hWndTarget As IntPtr = pr.MainWindowHandle
ShowWindow(hWndTarget, SW_SHOWMINIMIZED)

Declarations :

Public Const SW_SHOWMINIMIZED As Integer = 2
<DllImport("User32.dll", EntryPoint:="ShowWindow", SetLastError:=True)>
  Public Shared Function ShowWindow(ByVal hWnd As IntPtr, nShowCmd As Integer) As Boolean
  End Function

Answer 2

    Private Const SW_HIDE = 0
    Private Sub Form648_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Process.Start("C:\Program Files\Random\Randoms.exe")
        Dim ClientProcess As Process = Process.GetProcessesByName("RandomSLtF").FirstOrDefault
        If ClientProcess IsNot Nothing Then
            SendMessage(ClientProcess.MainWindowHandle, SW_HIDE = 0)
        End If

    End Sub

You should not use GetProcess to get the process handle of a process that you create.  The override of the Process.Start method returns the process object.  That object provides the methods needed to manage the process.
https://msdn.microsoft.com/en-us/library/0w4h05yb(v=vs.110).aspx

Answer 3

As Acamar has pointed out, the StartInfo property should be used.  In particular, set the StartInfo property's WindowStyle to Minimized.

Answer 4

Thanks for the help Castorix31, and thanks for everyone's input :)

Answer 5

 The WaitForInputIdle method does not always work and is not really reliable for doing what it says it does.  There is also no way to tell how long a process will take to load.  It would depend on the process itself and if the system is busy or not at the time the process is starting.  Using the Thread.Sleep method would be slightly more reliable but,  it has its downfalls too.

Imports System.Runtime.InteropServices

Public Class Form1
    <DllImport("user32.dll", EntryPoint:="SendMessageW")>
    Public Shared Function SendMessageW(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As UInteger, ByVal lParam As Integer) As Integer
    End Function

    Private Const WM_SYSCOMMAND As Integer = &H112
    Private Const SC_MINIMIZE As Integer = &HF020

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim p As Process = Process.Start("C:\Users\?????\Documents\Visual Studio 2015\Projects\Borderless Test Form\Borderless Test Form\bin\Debug\Borderless Test Form.exe")
        Threading.Thread.Sleep(1000) 'wait 1 second
        SendMessageW(p.MainWindowHandle, WM_SYSCOMMAND, SC_MINIMIZE, 0)
    End Sub
End Class

 

 Here is a reliable method to detect when a window has actually been created...

Imports System.ComponentModel
Imports System.Runtime.InteropServices

Public Class Form1
    Private hEventHook As IntPtr
    Private EventHookDel As New WINEVENTPROC(AddressOf EventCallback)

    Private Const WINEVENT_OUTOFCONTEXT As Integer = &H0
    Private Const EVENT_OBJECT_CREATE As Integer = &H8000
    Private Const WM_SYSCOMMAND As Integer = &H112
    Private Const SC_MINIMIZE As Integer = &HF020

    <DllImport("user32.dll", EntryPoint:="SendMessageW")>
    Public Shared Function SendMessageW(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As UInteger, ByVal lParam As Integer) As Integer
    End Function

    <DllImport("user32.dll")>
    Private Shared Function SetWinEventHook(ByVal eventMin As UInteger, ByVal eventMax As UInteger, ByVal hmodWinEventProc As IntPtr, ByVal pfnWinEventProc As WINEVENTPROC, ByVal idProcess As UInteger, ByVal idThread As UInteger, ByVal dwFlags As UInteger) As IntPtr
    End Function

    <UnmanagedFunctionPointer(CallingConvention.StdCall)>
    Private Delegate Sub WINEVENTPROC(ByVal hWinEventHook As IntPtr, ByVal [event] As UInteger, ByVal hwnd As IntPtr, ByVal idObject As Integer, ByVal idChild As Integer, ByVal idEventThread As UInteger, ByVal dwmsEventTime As UInteger)

    <DllImport("user32.dll")> Private Shared Function UnhookWinEvent(ByVal hWinEventHook As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        hEventHook = SetWinEventHook(EVENT_OBJECT_CREATE, EVENT_OBJECT_CREATE, IntPtr.Zero, EventHookDel, 0, 0, WINEVENT_OUTOFCONTEXT)
    End Sub

    Private Sub Form1_Closing(sender As Object, e As CancelEventArgs) Handles Me.Closing
        UnhookWinEvent(hEventHook)
    End Sub

    Private Filename As String = "C:\Users\?????\Documents\Visual Studio 2015\Projects\Borderless Test Form\Borderless Test Form\bin\Debug\Borderless Test Form.exe"

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Process.Start(Filename)
    End Sub

    Private Sub EventCallback(ByVal hWinEventHook As IntPtr, ByVal [event] As UInteger, ByVal hwnd As IntPtr, ByVal idObject As Integer, ByVal idChild As Integer, ByVal idEventThread As UInteger, ByVal dwmsEventTime As UInteger)
        If [event] = EVENT_OBJECT_CREATE Then
            Dim p As Process = Process.GetProcesses.Where(Function(x) x.MainWindowHandle = hwnd AndAlso x.ProcessName.ToLower = IO.Path.GetFileNameWithoutExtension(Filename).ToLower).FirstOrDefault
            If p IsNot Nothing Then
                SendMessageW(p.MainWindowHandle, WM_SYSCOMMAND, SC_MINIMIZE, 0)
            End If
        End If
    End Sub
End Class

EDIT: Changed code a little.  By the way,  this editor for the forum SUCKS!!!!

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If you say it can`t be done then i`ll try it

Answer 6

Thank you!