c# - 关于按钮结束运行方法的不同方法

Question

所以我有一些代码可以检查插件和 USB 设备的删除。

public void Main_Shown(object sender, EventArgs e)
        {
            var watcheradd = new ManagementEventWatcher();
            var queryadd = new WqlEventQuery("SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 2");
            watcheradd.EventArrived += new EventArrivedEventHandler(watcher_deviceadded);
            watcheradd.Query = queryadd;
            watcheradd.Start();


            var watcherremove = new ManagementEventWatcher();
            var queryremove = new WqlEventQuery("SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 3");
            watcherremove.EventArrived += new EventArrivedEventHandler(watcher_deviceremoved);
            watcherremove.Query = queryremove;
            watcherremove.Start();   
}

我想知道无论如何我可以在我的程序退出之前停止watchremoveandwatcheradd循环，以防止其中的停止代码出现异常：

     private void Exit_Main(object sender, EventArgs e)
    {
        Process p = new System.Diagnostics.Process();
        ProcessStartInfo si = new System.Diagnostics.ProcessStartInfo();
        si.RedirectStandardInput = false;
        si.CreateNoWindow = true;
        si.UseShellExecute = false;
        si.FileName = "adb.exe";
        si.Arguments = "kill-server";
        p = Process.Start(si);
        p.WaitForExit();

        Application.Exit();
        //EXIT APPLICATION!!!            
    }

因为Main_Shown.deviceadd.Stop();这不是正确的语法或方法。结果应该安全地停止上述循环，然后允许程序无异常退出。

Answer 1

得到了解决方案。所以我需要添加

 ManagementEventWatcher watcheradd = new ManagementEventWatcher();
    WqlEventQuery queryadd = new WqlEventQuery();
    ManagementEventWatcher watcherremove = new ManagementEventWatcher();
    WqlEventQuery queryremove = new WqlEventQuery();

在类之上，并将类设置为全局。所以现在它可以使用下面的代码毫无问题地退出。

`si.FileName = "adb.exe";
        si.Arguments = "kill-server";
        p = Process.Start(si);
        p.WaitForExit();
        watcherremove.Stop();
        watcheradd.Stop();
        Application.Exit();
        //EXIT APPLICATION!!`

感谢大家的帮助。