c# – 获取所有打开的窗口

public delegate bool Win32Callback(IntPtr hwnd,IntPtr lParam);

[DllImport("user32.dll")]
public static extern uint GetWindowThreadProcessId(IntPtr hWnd,out uint lpdwProcessId);

[DllImport("user32.Dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool EnumChildWindows(IntPtr parentHandle,Win32Callback callback,IntPtr lParam);

static void Main(string[] args)
{
    Process[] processes = Process.GetProcessesByName("MyApp");

    var windows = new List<IntPtr>();

    foreach (Process p in processes)
    {
        IEnumerable<IntPtr> w = GetRootWindowsOfProcess(p.Id);
        windows.AddRange(w);
    }
}

private static IEnumerable<IntPtr> GetRootWindowsOfProcess(int pid)
{
    IEnumerable<IntPtr> rootWindows = GetChildWindows(IntPtr.Zero);
    var dsProcRootWindows = new List<IntPtr>();
    foreach (IntPtr hWnd in rootWindows)
    {
        uint lpdwProcessId;
        GetWindowThreadProcessId(hWnd,out lpdwProcessId);
        if (lpdwProcessId == pid)
            dsProcRootWindows.Add(hWnd);
    }
    return dsProcRootWindows;
}

private static IEnumerable<IntPtr> GetChildWindows(IntPtr parent)
{
    var result = new List<IntPtr>();
    GCHandle listHandle = GCHandle.Alloc(result);
    try
    {
        var childProc = new Win32Callback(EnumWindow);
        EnumChildWindows(parent,childProc,GCHandle.ToIntPtr(listHandle));
    }
    finally
    {
        if (listHandle.IsAllocated)
            listHandle.Free();
    }
    return result;
}

private static bool EnumWindow(IntPtr handle,IntPtr pointer)
{
    GCHandle gch = GCHandle.FromIntPtr(pointer);
    var list = gch.Target as List<IntPtr>;
    if (list == null)
    {
        throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
    }
    list.Add(handle);
    //  You can modify this to check to see if you want to cancel the operation,then return a null here
    return true;
}

现在作为提到的评论者之一,您不应该有多个线程在做GUI工作.一个线程应该进行GUI绘图,而其他线程执行实际的其他工作.