What is the "right" way to bring a Windows Forms Application to the foreground?

user_39430 0
Viewed 43862

I am writing a Windows Forms Application in C#. I need to be able to bring it to the foreground. After some Googling and experimentation, I have a working solution that looks pretty hacky.

I would like to know the elegant way to do this, if there is one. I need the app to restore and come to the foreground whether it was minimized, or not minimized but in background.

Current code looks like this:

WindowState = FormWindowState.Minimized;
WindowState = FormWindowState.Normal;
BringToFront();
Focus();
visual-studio-2008 winforms c#
12 Answers
user_85968790

As already stated in another response, one (of course unelegant) way to do this would be by using user32.dll and call the native methods, this can be valid if we are using some unlinked process or thread from the window caller, that was set in the main caller as a background window (eg: always on top for the window that we want topmost).

this was partially copied, but only for easyness:

public enum WindowPos : int
{
    HWND_NOTOPMOST=-2,
    HWND_TOPMOST=-1,
    HWND_TOP=0,
    HWND_BOTTOM=1
}
public enum WindowFlags : uint
{
    SWP_NOSIZE=0x0001,
    SWP_NOMOVE=0x0002,
    SWP_NOZORDER=0x0004,
    SWP_NOREDRAW=0x0008,
    SWP_NOACTIVATE=0x0010,
    SWP_FRAMECHANGED=0x0020,  /* The frame changed: send WM_NCCALCSIZE */
    SWP_SHOWWINDOW=0x0040,
    SWP_HIDEWINDOW=0x0080,
    SWP_NOCOPYBITS=0x0100,
    SWP_NOOWNERZORDER=0x0200,  /* Don't do owner Z ordering */
    SWP_NOSENDCHANGING=0x0400  /* Don't send WM_WINDOWPOSCHANGING */
}
public enum ShowWindowCommands : int
{
    SW_HIDE=0,
    SW_SHOWNORMAL=1,
    SW_NORMAL=1,
    SW_SHOWMINIMIZED=2,
    SW_SHOWMAXIMIZED=3,
    SW_MAXIMIZE=3,
    SW_SHOWNOACTIVATE=4,
    SW_SHOW=5,
    SW_MINIMIZE=6,
    SW_SHOWMINNOACTIVE=7,
    SW_SHOWNA=8,
    SW_RESTORE=9,
    SW_SHOWDEFAULT=10,
    SW_FORCEMINIMIZE=11,
    SW_MAX=11
}

private static class User32
{
    [DllImport("user32.dll")]
    internal static unsafe extern IntPtr SetForegroundWindow(IntPtr hWnd);

    [DllImport("user32.dll")]
    internal static unsafe extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

    [DllImport("user32.dll")]
    internal static unsafe extern bool SetWindowPos(IntPtr hWnd, int hWndPutAfter, int x, int y, int cx, int cy, uint flags);

    [DllImport("user32.dll")]
    internal static unsafe extern IntPtr SetFocus( IntPtr hWnd );
}
public void Activate()
{
    Process currentProcess = Process.GetCurrentProcess();
    IntPtr hWnd = currentProcess.MainWindowHandle;
    if (hWnd != IntPtr.Zero)
    {
        User32.SetWindowPos(hWnd, (int)WindowPos.Top, 0, 0, 0, 0, (uint)(WindowFlags.SWP_NOMOVE | WindowFlags.SWP_NOSIZE));
        User32.ShowWindow(hWnd, (int)ShowWindowCommands.SW_SHOW);
        User32.SetForegroundWindow(hWnd);
        User32.SetFocus( hWnd );
    }
}

For completeness I added most references from the constants that are available in the windows SDK

user_65710530
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