Find if a file is present

Question

I was wondering how to find if a file is present in the C:\ drive. And if it is, display a picture box on the form. What do I need to include and what do I need to use, and where do I place the code? Thanks.

Answer 1

You can use File.Exists("SomeFileName.txt").

--
Mike

Answer 2

So you can do,

if(file->Exists("File.exe")){

//code here

}

Will it work in all files and folders? I want to make it goto C:\MyProgram\Add-Ons

Answer 3

Make it like this,

if(File.Exists(@"C:\MyProgram\Add-Ons\File.exe")
{
// code here
}

http://msdn.microsoft.com/en-us/library/system.io.file.exists.aspx

Hope it helps!!!

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Regards Vallarasu S. FSharpMe.blogspot.com

Answer 4

Hi,

you got already a pointer to File.Exists, but maybe you want your appluication to be aware on file changes. In such a case you could use the FileSystemWatcher (http://msdn.microsoft.com/en-us/library/System.IO.FileSystemWatcher.aspx). This could be usefull if you want to be informed in case a file is created or deleted while your application runs and it will take away the need to write your own code to check a file system over and over in a loop.

With kind regards,

Konrad

Answer 5

I tried Vallarasu's method. Here are the errors:

error C2018: unknown character '0x40'

warning C4129: 'g' : unrecognized character escape sequence

warning C4129: 'p' : unrecognized character escape sequence

warning C4129: 'h' : unrecognized character escape sequence

I am currently using C++. Do I use it like: "if(File::Exist(@"C:\MyProgramFile\Add-Ons\File.exe)"?

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---------- PressOnThis

Answer 6

I tried this, but nothing happened... I tested it with a text document called "hi.txt" Le codez:

this->FileSystemWatcher->Filter = L"C:\\MyProgramName\\Add-ons\\hi.txt";

this->PlugInChecker->Path = L"C:\\MyProgramName\\Add-ons\\";

private: System::Void PlugInChecker_Created(System::Object^  sender, System::IO::FileSystemEventArgs^  e) {

MessageBox::Show("Yay! IT worked :P");

}

I'm probobly coding wrong. Help?

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---------- PressOnThis

Answer 7

Try this:

using namespace System;
using namespace System::IO;

int main() {
    String* path = S"c:\\temp\\MyTest.txt";
    String* path2 = String::Concat(path, S"temp");
    try {
        StreamWriter* sw = File::CreateText(path);
        if (sw) __try_cast<IDisposable*>(sw)->Dispose();

        // Only do the Copy operation if the first file exists
        // and the second file does not.
        if (File::Exists(path)) {
            if (File::Exists(path2)) {
                Console::WriteLine(S"The target already exists");
            } else {
                // Try to copy the file.
                File::Copy(path, path2);
                Console::WriteLine(S"{0} was copied to {1}.", path, path2);
            }
        } else {
            Console::WriteLine(S"The source file does not exist.");
        }
    } catch (Exception*) {
        Console::WriteLine(S"Double copying is not allowed, as expected.");
    }
}

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Mitja

Answer 8

I tried Vallarasu's method. Here are the errors:

error C2018: unknown character '0x40'

warning C4129: 'g' : unrecognized character escape sequence

warning C4129: 'p' : unrecognized character escape sequence

warning C4129: 'h' : unrecognized character escape sequence

I am currently using C++. Do I use it like: "if(File::Exist(@"C:\MyProgramFile\Add-Ons\File.exe)"?

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---------- PressOnThis

Hi PressOnThis,

The code in c++ should be 

bool bReturn = System::IO::File::Exists("C:\\MyProgramFile\\Add-Ons\\File.exe");

In addition, I suggest you ask c++ issue in the Visual C++ Forums which you can get better support.

Best Regards,

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Bob Wu [MSFT]
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