C#程序运行错误解决一例

MSDN中有一段示例:

 

EventQuery 类

下面的示例演示当由于事件类是 __InstanceCreationEvent 而创建 Win32_Process 的实例时，客户端如何接收通知。有关更多信息，请参见位于 上的 MSDN Library 中的“Windows Management Instrumentation”文档。客户端通过调用 方法来同步接收事件。在运行此代码示例的同时，可以启动进程（如记事本）来测试此示例。

using System;
using System.Management;

// This example shows synchronous consumption of events.
// The client is blocked while waiting for events.

public class EventWatcherPolling
{
    public static int Main(string[] args)
    {
        // Create event query to be notified within 1 second of
        // a change in a service
        EventQuery query = new EventQuery();
        query.QueryString = "SELECT * FROM" +
            " __InstanceCreationEvent WITHIN 1 " +
            "WHERE TargetInstance isa "Win32_Process"";

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(query);
        // times out watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = new TimeSpan(0,0,5);
     
        // Block until the next event occurs
        // Note: this can be done in a loop if waiting for
        //        more than one occurrence
        Console.WriteLine(
            "Open an application (notepad.exe) to trigger an event.");
        ManagementBaseObject e = watcher.WaitForNextEvent();

        //Display information from the event
        Console.WriteLine(
            "Process {0} has been created, path is: {1}",
            ((ManagementBaseObject)e
            ["TargetInstance"])["Name"],
            ((ManagementBaseObject)e
            ["TargetInstance"])["ExecutablePath"]);

        //Cancel the subscription
        watcher.Stop();
        return 0;
    }
}

 

编译成功,运行时出现异常:

Open an application (notepad.exe) to trigger an event.

Unhandled Exception: System.Runtime.InteropServices.COMException (0x800706BA): T
he RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
   at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 e
rrorCode, IntPtr errorInfo)
   at System.Management.ManagementEventWatcher.WaitForNextEvent()
   at EventWatcherPolling.Main(String[] args)

 

经GOOGLE到

受到提示打开

DCOM Server Process Launcher

服务,就正常了.