Sending key strokes to another application

Question

hi i wanted to write a windows application that sends keyboard strokes to another application something like a virtual keyboard.

i researched the subject and read few articles.
i managed to find a code that partially works.

in the sample code above i'm trying to send strokes to a word file.
it workes partially in the first send and then it just stopps doing what it supposed to.

the code is:
// Get a handle to an application window.
[DllImport("USER32.DLL", CharSet = CharSet.Unicode)]
public static extern IntPtr FindWindow(string lpClassName,
string lpWindowName);
// Activate an application window.
[DllImport("USER32.DLL")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
IntPtr wordHandle = FindWindow(null, "New Microsoft Word Document.doc - Microsoft Word");
// Verify that word is a running process.
if (wordHandle == IntPtr.Zero)
{
MessageBox.Show("word is not running.");
return;
}
SetForegroundWindow(wordHandle);
SendKeys.SendWait("{a}");

any help will be appreciated.

Sam Hobbs · Answer

Sending keys to other applications is often more difficult than most people think. One problem is that the keys must go to a specific control and that control must have focus. Another common problem is timing; sometimes it is necessary to include a delay. It might be easier and more reliable to send the data more directly.

emilio · Answer

i added a short delay before i sent the strokes and it solved the problem. thanks everyone for the help

Aleksandar Ilioski · Answer

You can allso try this.. [DllImport(USER32.DLLEntryPoint = FindWindow)] public static extern IntPtr NajdiProzorec(string lpClassName string lpWindowName); [DllImport(USER32.DLL)] public static extern bool SetForegroundWindow(IntPtr hWnd); private void button1_Click(object sender EventArgs e) { IntPtr wH = NajdiProzorec(BaseWindow_RootWnd Player Window); if (wH== IntPtr.Zero) { MessageBox.Show(Winamp is not running.); System.Diagnostics.Process.Start(C:\Program Files\Winamp\winamp.exe); return; } SetForegroundWindow(wH); SendKeys.SendWait(v); SendKeys.SendWait(nul); SendKeys.SendWait({ESC}); SendKeys.SendWait(l); SendKeys.SendWait({ESC}); SendKeys.SendWait(soft); SendKeys.SendWait(x); } the winamp shoud start bilnk at the ritham..

Aleksandar Ilioski · Answer

i have read about this.. few months ago.. and find two solutions.. one is simular to the one you use.. and this is the another.. [DllImport(user32.dll SetLastError = true)] static extern IntPtr FindWindowEx(IntPtr hwndParent IntPtr hwndChildAfter string lpszClass string lpszWindow); [DllImport(User32.Dll EntryPoint = PostMessageA)] static extern bool PostMessage(IntPtr hWnd uint msg int wParam int lParam); [DllImport(user32.dll)] static extern byte VkKeyScan(char ch); const uint WM_KEYDOWN = 0x100; private void button2_Click(object sender EventArgs e) { Process[] procs = Process.GetProcessesByName(Notepad); foreach (Process proc in procs) { // look for untitled notepad window if (proc.MainWindowTitle == Untitled - Notepad) { // get handle to Notepad's edit window IntPtr hWnd = FindWindowEx(proc.MainWindowHandle IntPtr.Zero edit null); // post hello to notepad string s = hello; for (int i = 0; i { PostMessage(hWnd WM_KEYDOWN VkKeyScan(s[i]) 0); } break; } } } both of them work fine for me.. i don't know why you saing that it is not working..