需要帮助WMI ManagementEventWatcher无效的类异常` [英] Need Help WMI ManagementEventWatcher Invalid Class Exception`
问题描述
我一直在与我刚开始时以为是一个小问题的斗争，而现在却使我陷入困惑的一天.我试图实例化一个ManagementEventWatcher来监视我的PC上的时钟并仅显示时间.问题 我遇到的问题是，观察者一启动，它就会抛出一个无效类，该类将作为管理异常抛出.
I've been battling what I thought would be a small problem when I started it, to what has now caused me to a day or so of puzzlement. I am trying to instantiate a ManagementEventWatcher to monitor the clock on my pc and simply display the time. The problem I am running into is that as soon as the watcher starts, it throws and invalid class that is being thrown as a management exception.
我在论坛上关注了一些话题，并认为可能需要为观察者指定一个事件类名称，但是我认为我将在此处发布代码，以便也许有人会看到我正在创建的问题.为我自己.
I followed a few threads here on the forums, and thought it might be that I need to specify an eventclassname for the watcher, but I thought I would post the code here, so that perhaps someone might see the problem I am creating for myself.
由于我与WMI的合作不多，因此非常感谢任何帮助！
As I have not worked much with WMI, any help is much appreciated!
平台:Windows 7
Platform: Windows 7
Visual Studio 2010
Visual Studio 2010
----------代码开始------------------------
---------- code begins------------------------
///< summary>
///MainWindow.xaml的交互逻辑
///</summary>
公共局部类MainWindow:Window
{
ManagementEventWatcher watcher =新的ManagementEventWatcher();
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
ManagementEventWatcher watcher = new ManagementEventWatcher();
公共MainWindow()
{
InitializeComponent();
}
public MainWindow()
{
InitializeComponent();
}
私有void Window_Loaded(对象发送者，RoutedEventArgs e)
{
MessageBox.Show(该应用已启动.");
//此命名空间中定义的eventreceiver
EventReceiver接收器=新的EventReceiver();
private void Window_Loaded(object sender, RoutedEventArgs e)
{
MessageBox.Show("The App started..");
//eventreceiver defined in this namespace
EventReceiver receiver = new EventReceiver();
//创建观察者并注册回调
watcher = GetWatcher(new EventArrivedEventHandler(receiver.OnEventArrived));
//观察者开始收听管理事件
试试
{
watcher.Start();
}
抓住(AccessViolationException ex)
{
MessageBox.Show(ex.Message +访问异常");
}
捕捉(ManagementException ex)
{
MessageBox.Show(ex.Message +"management exception");
}
catch(异常例外)
{
MessageBox.Show(ex.Message +一般异常");
}
}
//create watcher and register the callback
watcher = GetWatcher(new EventArrivedEventHandler(receiver.OnEventArrived));
//watcher starts to listen to management events
try
{
watcher.Start();
}
catch (AccessViolationException ex)
{
MessageBox.Show(ex.Message + " access exception");
}
catch (ManagementException ex)
{
MessageBox.Show(ex.Message + " management exception");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message + " general exception");
}
}
私有void Window_Closing(对象发送者，System.ComponentModel.CancelEventArgs e)
{
watcher.Stop();
}
private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
watcher.Stop();
}
公共静态ManagementEventWatcher GetWatcher(EventArrivedEventHandler处理程序)
{
//创建事件查询，以便在服务更改后1秒钟内得到通知
WqlEventQuery查询=新的WqlEventQuery("_ InstanceModificationEvent"，新的TimeSpan(0，0，1)，
"TargetInstance是一个'Win32_Localtime'AND". +" TargetInstance.Second = 0");
ManagementScope范围=新的ManagementScope(@" \\.\ root \ default "));
//初始化事件观察者并订阅与该查询匹配的事件
ManagementEventWatcher watcher =新的ManagementEventWatcher(scope，query);
//使用
//必需的处理程序，以允许观察者与应用进行通信
watcher.EventArrived + =新的EventArrivedEventHandler(handler);
返回观察者；
}
}
public static ManagementEventWatcher GetWatcher(EventArrivedEventHandler handler)
{
//create event query to be notified within 1 second of a change in a service
WqlEventQuery query = new WqlEventQuery("_InstanceModificationEvent", new TimeSpan(0, 0, 1),
"TargetInstance isa 'Win32_Localtime' AND " + "TargetInstance.Second = 0");
ManagementScope scope = new ManagementScope(@"\\.\root\default");
//initialize an event watcher and subscribe to events that match this query
ManagementEventWatcher watcher = new ManagementEventWatcher(scope,query);
//attach the event arrived property to eventarrivedeventhandler method with the
//required handler to allow watcher to communicate to the app
watcher.EventArrived += new EventArrivedEventHandler(handler);
return watcher;
}
}
公共类EventReceiver
{
公共无效OnEventArrived(对象发送者，EventArrivedEventArgs e)
{
ManagementBaseObject evt = e.NewEvent;
public class EventReceiver
{
public void OnEventArrived(object sender, EventArrivedEventArgs e)
{
ManagementBaseObject evt = e.NewEvent;
//显示事件的信息
字符串时间= string.Format("{0}:{1:00}"，
((ManagementBaseObject)evt ["TargetInstance"]] ["Hour"]，
((ManagementBaseObject)evt ["TargetInstance"]] ["Minute"]));
//display information for the event
string time = string.Format("{0}:{1:00}",
((ManagementBaseObject)evt["TargetInstance"])["Hour"],
((ManagementBaseObject)evt["TargetInstance"])["Minute"]);
MessageBox.Show(时间，当前时间");
}
}
MessageBox.Show(time, "Current time");
}
}
-------代码结尾-------
推荐答案
尝试使用:
//WqlEventQuery query = new WqlEventQuery();
// query.EventClassName =" __ InstanceModificationEvent" ;;
// query.Condition = @"quot; TargetInstance ISA'Win32_LocalTime'AND TargetInstance.Hour = 0 AND
//TargetInstance.Minute = 0 AND TargetInstance.Second = 0" ;;
// WqlEventQuery query = new WqlEventQuery();
// query.EventClassName = "__InstanceModificationEvent ";
// query.Condition = @"TargetInstance ISA 'Win32_LocalTime' AND TargetInstance.Hour = 0 AND
//TargetInstance.Minute = 0 AND TargetInstance.Second = 0";
如何使用计时器对象?
哈里
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