Send Command by .Net Application in Another Running application in Windows

Kunal Vaishya

Dear Friends ,
I want to send command to another running application in windows by .Net Desktop application. How can i send it can any one help me ?

3 Replies

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Vulpes14y ago
It's possible but fiddly.

There are always synchronization issues with stuff like this and you have to experiment with different delays when sending multiple keystroke combinations to give the application's UI time to react.

The following worked OK for me when I tried it just now:

using System;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Windows.Forms;
using System.Threading;

class Test
{
[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);

static void Main()
{
Process[] procs = Process.GetProcessesByName("winword");
if (procs.Length > 0)
{
IntPtr hWnd = procs[0].MainWindowHandle;
SetForegroundWindow(hWnd);
SendKeys.SendWait("abc");
Thread.Sleep(2000);
SendKeys.SendWait("{F12}");
Thread.Sleep(2000);
SendKeys.SendWait("abc.txt");
Thread.Sleep(2000);
SendKeys.SendWait("~");
}
}
}

For a list of keyboard shortcuts for MS Word see here:

http://support.microsoft.com/kb/290938
Kunal Vaishya14y ago
Hi Vulpes thankx for reply

i want to do like Ms Word is Open in i want type something , set format and save as by Using .Net is it possible by this
Vulpes14y ago
If the other application has a keyboard interface, then the easiest way is to send it some keys using the SendKeys.Send (or SendWait) method:

http://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.send.aspx

However, before you can do this you need to force focus onto the other application. This can be done using the SetForegroundWindow API function whose signature is:

using System.Runtime.InteropServices;

//...

[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);

If it's the application's main window that you need to send the keystrokes to, then an easy way to get its window handle (hWnd parameter in the above function) is to use the Process class:

using System.Diagnostics;

// ....

Process[] procs = Process.GetProcessesByName("notepad"); // or whatever name of application is
if (procs.Length > 0)
{
IntPtr hWnd = procs[0].MainWindowHandle;
SetForegroundWindow(hWnd);
// send it some keys
}