Once you have the Process, you can enumerate all the Windows in the process and test if any of them match the window you are looking for.
You will need the following P/Invoke declarations
[DllImport("user32", SetLastError=true)]
[return: MarshalAs(UnmanagedType.Bool)]
private extern static bool EnumThreadWindows(int threadId, EnumWindowsProc callback, IntPtr lParam);
[DllImport("user32", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumChildWindows(IntPtr hwndParent, EnumWindowsProc lpEnumFunc, IntPtr lParam);
[DllImport("user32", SetLastError = true, CharSet = CharSet.Auto)]
private extern static int GetWindowText(IntPtr hWnd, StringBuilder text, int maxCount);
The followng is an example of a pair of functions that can be used to find the windows in a specific process, I understood from your question that you have the Process, the problem is enumerating the windows.
public static IntPtr FindWindowInProcess(Process process, Func<string, bool> compareTitle)
{
IntPtr windowHandle = IntPtr.Zero;
foreach (ProcessThread t in process.Threads)
{
windowHandle = FindWindowInThread(t.Id, compareTitle);
if (windowHandle != IntPtr.Zero)
{
break;
}
}
return windowHandle;
}
private static IntPtr FindWindowInThread(int threadId, Func<string, bool> compareTitle)
{
IntPtr windowHandle = IntPtr.Zero;
EnumThreadWindows(threadId, (hWnd, lParam) =>
{
StringBuilder text = new StringBuilder(200);
GetWindowText(hWnd, text, 200);
if (compareTitle(text.ToString()))
{
windowHandle = hWnd;
return false;
}
return true;
}, IntPtr.Zero);
return windowHandle;
}
Then you can call the FindWindowInProcess function to find a window that's title ends with "ABC" as an example.
IntPtr hWnd = FindWindowInProcess(p, s => s.EndsWith("ABC"));
if (hWnd != IntPtr.Zero)
{
// The window was found....
}
Of course you can replace s => s.EndsWith("ABC") with any expression that will satisfy your search criteria for the window, it could be a regex etc.
Here is also a version of FindThreadWindow that will also check the first level of child windows. You could take this further and make it a recursive function if your windows is deeper down in the hierarchy.
private static IntPtr FindWindowInThread(int threadId, Func<string, bool> compareTitle)
{
IntPtr windowHandle = IntPtr.Zero;
EnumThreadWindows(threadId, (hWnd, lParam) =>
{
StringBuilder text = new StringBuilder(200);
GetWindowText(hWnd, text, 200);
if (compareTitle(text.ToString()))
{
windowHandle = hWnd;
return false;
}
else
{
windowHandle = FindChildWindow(hWnd, compareTitle);
if (windowHandle != IntPtr.Zero)
{
return false;
}
}
return true;
}, IntPtr.Zero);
return windowHandle;
}
private static IntPtr FindChildWindow(IntPtr hWnd, Func<string, bool> compareTitle)
{
IntPtr windowHandle = IntPtr.Zero;
EnumChildWindows(hWnd, (hChildWnd, lParam) =>
{
StringBuilder text = new StringBuilder(200);
GetWindowText(hChildWnd, text, 200);
if (compareTitle(text.ToString()))
{
windowHandle = hChildWnd;
return false;
}
return true;
}, IntPtr.Zero);
return windowHandle;
}