有的程序可以打开多个窗口并显示在任务栏上。某些情况下，我们需要找到窗口做些事情时，可以参考下面的代码。

public static class Win32Api{[DllImport("user32.dll", SetLastError = true)]public static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam);public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);[DllImport("user32.dll", SetLastError = true)]public static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);[DllImport("user32.dll")]public static extern bool IsWindowVisible(IntPtr hWnd);[DllImport("user32.dll", SetLastError = true)]public static extern IntPtr GetWindow(IntPtr hWnd, GetWindow_Cmd uCmd);public enum GetWindow_Cmd : uint{GW_HWNDFIRST = 0,GW_HWNDLAST = 1,GW_HWNDNEXT = 2,GW_HWNDPREV = 3,GW_OWNER = 4,GW_CHILD = 5,GW_ENABLEDPOPUP = 6}}class Program{static void Main(string[] args){GetWindowCount(Process.GetProcessesByName("myapp")[0]);}private static void GetWindowCount(Process process){int windowCount = 0;Thread.Sleep(1000);int processId = process.Id;Win32Api.EnumWindows((IntPtr hWnd, IntPtr lParam) =>{int id;Win32Api.GetWindowThreadProcessId(hWnd, out id);IntPtr parentWindow = Win32Api.GetWindow(hWnd, Win32Api.GetWindow_Cmd.GW_OWNER);if (id == processId && parentWindow == IntPtr.Zero && Win32Api.IsWindowVisible(hWnd)){windowCount++;}return true;}, IntPtr.Zero);Debug.WriteLine($"process window: {windowCount}");}}