How to bring a window foreground using c#?

问题:

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.

回答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

回答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);
    }

回答3:

In order for SetForegroundWindow to work consistently, you have to meet a few criteria. The first is your process that would run the command must be in the foreground. Only foreground process can make another process foreground. In order to make your process foreground first, you have to bring the main window to the front, if it is not. You minimise it first and then SetForegroundWindow it, to make it foreground. Now find the target process and bring it to the front

The steps are

• Minimise the current window
• SetForegroundWindow it
• Find the target process
• SetForegroundWindow it

I've got an example, though it's a slightly different use case.

回答4:

You should use SetForegroundWindow. Also it may be interesting for you C# Force Form Focus

回答5:

I'll be brief: Form.BringToFront()

回答6:

As of Windows 7 these features dont behave quite so well. If there is an application such as Excel in front of the application you want to bring to the front then Windows 7 blocks this and flashes the window. You can set a registry timeout setting ForegroundLockTimeout=0 in HKEY_CURRENT_USER\Control Panel\Desktop but these is known as stealing focus. To set the behaviour of how XP "should" behave and will behave in Windows 7 by default you can create/set the value to 0x00030D40 (200000ms). I'd like to know what is the preferred solution for trusted Windows applications. eg. If I trust application B to take focus when I double click something in Application A, and some other app is obscuring the window of Application B.