JAVA高级面试进阶训练营视频教程

admin

　　程序猿对于宕机再熟悉不过了，如果一个程序异常退出，那我们只能在Windows日志中找到它的踪迹；如果它是一个托盘程序，异常退出后，它会停留在托盘中久久不能离去，直到我们的鼠标从它身上划过；如果一个程序被另一个守护程序不断的杀掉、重启，那么它的结果会如下图所示，

　　请注意！！这不是扫雷！！没错，这正是残留的图标。解决方法其实很简单，在程序每次开启前，向托盘窗口发送鼠标经过消息WM_MOUSEMOVE，使其刷新。

　　首先要明确一点，托盘包括显示区域和溢出区域，所以需要同时刷新，防止遗漏。可以用Spy++鼠标右键选择“突出显示”，窗口轮廓就会闪烁，SysPager和NotifyIconOverflowWindow。

代码如下：

using System;
using System.Runtime.InteropServices;
 
public class TaskBarUtil
{
    struct RECT
    {
        public int left, top, right, bottom;
    }
 
    public static void RefreshNotification()
    {
        var NotifyAreaHandle = GetNotifyAreaHandle();
        if (NotifyAreaHandle != IntPtr.Zero)
            RefreshWindow(NotifyAreaHandle);

        var NotifyOverHandle = GetNotifyOverHandle();
        if (NotifyOverHandle != IntPtr.Zero)
            RefreshWindow(NotifyOverHandle);
    }
 
    private static void RefreshWindow(IntPtr windowHandle)
    {
        const uint WM_MOUSEMOVE = 0x0200;
        RECT rect;
        GetClientRect(windowHandle, out rect);
        for (var x = 0; x < rect.right; x += 5)
            for (var y = 0; y < rect.bottom; y += 5)
                SendMessage(windowHandle, WM_MOUSEMOVE, 0, (y << 16) + x);
    }
 
    private static IntPtr GetNotifyAreaHandle()
    {
        var TrayWndHandle = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Shell_TrayWnd", string.Empty);
        var TrayNotifyWndHandle = FindWindowEx(TrayWndHandle, IntPtr.Zero, "TrayNotifyWnd", string.Empty);
        var SysPagerHandle = FindWindowEx(TrayNotifyWndHandle, IntPtr.Zero, "SysPager", string.Empty);
        var NotifyAreaHandle = FindWindowEx(SysPagerHandle, IntPtr.Zero, "ToolbarWindow32", string.Empty);

        return NotifyAreaHandle;
    }
  
    private static IntPtr GetNotifyOverHandle()
    {
        var OverHandle = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "NotifyIconOverflowWindow", string.Empty);
        var NotifyOverHandle = FindWindowEx(OverHandle, IntPtr.Zero, "ToolbarWindow32", string.Empty);
        
        return NotifyOverHandle;
    }
 
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
    [DllImport("user32.dll")]
    static extern bool GetClientRect(IntPtr handle, out RECT rect);
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    static extern IntPtr SendMessage(IntPtr handle, UInt32 message, Int32 wParam, Int32 lParam);
}

TaskBarUtil.RefreshNotification();

托盘又恢复往日简洁 ^_^