How to bring a window foreground using c#?

Question

I am trying to bring a window foreground. I am using this code. But its not working. Could someone please help?

ShowWindowAsync(wnd.hWnd, SW_SHOW);

SetForegroundWindow(wnd.hWnd);
// Code from Karl E. Peterson, www.mvps.org/vb/sample.htm
// Converted to Delphi by Ray Lischner
// Published in The Delphi Magazine 55, page 16
// Converted to C# by Kevin Gale
IntPtr foregroundWindow = GetForegroundWindow();
IntPtr Dummy = IntPtr.Zero;

uint foregroundThreadId = GetWindowThreadProcessId(foregroundWindow, Dummy);
uint thisThreadId = GetWindowThreadProcessId(wnd.hWnd, Dummy);

 if (AttachThreadInput(thisThreadId, foregroundThreadId, true))
 {
    BringWindowToTop(wnd.hWnd); // IE 5.5 related hack
    SetForegroundWindow(wnd.hWnd);
    AttachThreadInput(thisThreadId, foregroundThreadId, false);
 }

 if (GetForegroundWindow() != wnd.hWnd)
 {
     // Code by Daniel P. Stasinski
     // Converted to C# by Kevin Gale
    IntPtr Timeout = IntPtr.Zero;
    SystemParametersInfo(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, Timeout, 0);
    SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, Dummy, SPIF_SENDCHANGE);
    BringWindowToTop(wnd.hWnd); // IE 5.5 related hack
    SetForegroundWindow(wnd.hWnd);
    SystemParametersInfo(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, Timeout, SPIF_SENDCHANGE);
 }

Code Explained

Making a window the foreground window requires more than just calling the SetForegroundWindow API. You must first determine the foreground thread and attach it to your window, using AttachThreadInput, then call SetForegroundWindow. That way they can share input states.

First I call GetForegroundWindow to get the handle of the current foreground window. Then a few calls to GetWindowThreadProcessId retrieve the threads associated with the current foreground window and the window I want to bring to the foreground. If these threads are the same a simple call to SetForegroundWindow is all that is necessary. Otherwise, the foreground thread is attached to the window that I am bringing to the front and detached from what was the current foreground window. The AttachThreadInput API handles this.

Content Taken from here Thanks.

Answer 1

I've used this method before:

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

    Process[] processes = Process.GetProcessesByName("processname");
    SetForegroundWindow(processes[0].MainWindowHandle);

More information: http://pinvoke.net/default.aspx/user32.SetForegroundWindow

Answer 2

This code restores and set focus to a window:

    [DllImport("User32.dll")]
    static extern int SetForegroundWindow(IntPtr hWnd);

    [DllImport("user32.dll")]
    internal static extern bool SendMessage(IntPtr hWnd, Int32 msg, Int32 wParam, Int32 lParam);
    static Int32 WM_SYSCOMMAND = 0x0112;
    static Int32 SC_RESTORE = 0xF120;

And use it like this:

    var proc = Process.GetProcessesByName("YourProgram").FirstOrDefault();

    if (proc != null)
    {
        var pointer = proc.MainWindowHandle;

        SetForegroundWindow(pointer);
        SendMessage(pointer, WM_SYSCOMMAND, SC_RESTORE, 0);
    }