最近做了客户端的IM联系窗口的功能，有一个需求是如果收到新的消息时，任务栏需要闪烁提醒用户。 效果类似于微信和飞书收到新消息。
Windows有提供任务栏闪烁的API,直接调API即可。我这里把相关的功能都封装了一下，作为一个工具类，分享出来。 知识点：
- 从C#侧调用win32的 api
- 把win32 api需要的参数用struct的的形式声明出来，并且标注StructLayout.Sequntial
public static class WpfHelper
{
// 停止闪烁
public const uint FLASHW_STOP = 0;
// 闪烁窗口标题
public const uint FLASHW_CAPTION = 1;
// 闪烁任务栏按钮
public const uint FLASHW_TRAY = 2;
// 同时闪烁窗口标题和任务栏按钮
public const uint FLASHW_ALL = 3;
//持续闪烁，直到手动停止
public const uint FLASHW_TIMER = 4;
// 闪烁直到窗口获得焦点
public const uint FLASHW_TIMERNOFG = 12;
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool FlashWindowEx(ref FLASHWINFO pwfi);
[StructLayout(LayoutKind.Sequential)]
private struct FLASHWINFO
{
public uint cbSize;
public IntPtr hwnd;
public uint dwFlags;
public uint uCount;
public uint dwTimeout;
}
/// <summary>
/// 任务栏和指定窗口闪烁，直到该窗口获得焦点
/// </summary>
/// <param name="window"></param>
public static bool FlashTaskbarAndWindow(Window window)
{
FLASHWINFO fwi = new FLASHWINFO();
fwi.cbSize = Convert.ToUInt32(Marshal.SizeOf(fwi));
fwi.dwFlags = FLASHW_ALL | FLASHW_TIMER;
fwi.uCount = uint.MaxValue;
fwi.dwTimeout = 0;
if (window == null)
{
window = Application.Current.MainWindow;
}
var wih = new WindowInteropHelper(window);
fwi.hwnd = wih.Handle;
return FlashWindowEx(ref fwi);
}
/// <summary>
/// 暂停任务栏和指定窗口的闪烁
/// </summary>
/// <param name="window"></param>
public static bool StopFlashing(Window window)
{
FLASHWINFO fwi = new FLASHWINFO();
fwi.cbSize = Convert.ToUInt32(Marshal.SizeOf(fwi));
fwi.dwFlags = FLASHW_STOP;
fwi.uCount = uint.MaxValue;
fwi.dwTimeout = 0;
if (window == null)
{
window = Application.Current.MainWindow;
}
var wih = new WindowInteropHelper(window);
fwi.hwnd = wih.Handle;
return FlashWindowEx(ref fwi);
}
}
I have not failed. I’ve just found 10,000 ways that won’t work.