如何：记录多线程组件的事件

当记录多线程组件中的事件时，就应该考虑特殊注意事项了。 您必须提供一种方法来标识作为事件来源的线程。 还必须确保当记录事件时，线程不会互相干扰。 有关详细信息，请参见 事件日志和多线程组件。

在多线程应用程序中使用事件日志

1. 声明并创建事件日志。 有关详细信息，请参见 How to: Create and Remove Custom Event Logs。

2. 将每个线程的 Name 属性设置为唯一的标识符。

   Dim X as Integer
   X = 0
   Dim MyThread as New Threading.Thread(AddressOf MyMethod)
   MyThread.Name = "Thread number " & X.ToString
   ' Increments X so no other threads will share the same name.
   X += 1
   

   int X;
   X = 0;
   Thread MyThread = new Thread(new 
      ThreadStart(MyMethod));
   MyThread.Name = "Thread Number " + X.ToString();
   // Increments X so no other threads will share the same name.
   X += 1;
   

3. 为事件日志创建新的 Source，并将 Name 设置为与该线程对应的唯一字符串值。 有关如何创建 Source 的详细信息，请参见 How to: Add Your Application as a Source of Event Log Entries。

   Imports System.Threading
   ' Checks to see if there already is a source with the name of the 
   ' thread.
   If Not EventLog.SourceExists(Thread.CurrentThread.Name.ToString, _
      "myApplication") Then
      ' Creates a source with the name of the thread
      EventLog.CreateEventSource(Thread.CurrentThread.Name.ToString, _
         "MyApplication")
   End If
   

   // These lines go at the top of the code
   using System.Threading;
   using System.Diagnostics;
   // Checks to see if there already is a source with the name of the 
   // thread.
   if (!EventLog.SourceExists(CurrentThread.Name.ToString()))
      // Creates a source with the name of the thread.
      EventLog.CreateEventSource(CurrentThread.Name.ToString(), 
         "MyApplication");
   

4. 将事件日志的 Source 属性设置为该线程的名称，然后调用 WriteEntry 方法。

   提示

   确保在进行这些操作之前获得事件日志上的专用锁。

   ' Use the SyncLock keyword to obtain an exclusive lock on an object.
   SyncLock MyEventLog
     MyEventLog.Source = Thread.CurrentThread.Name.ToString
     EventLog.WriteEntry(Thread.CurrentThread.Name.ToString, _
        "Error in Widget 42")
   End SyncLock
   

   // Use the lock keyword to obtain an exclusive lock on an object
   lock(MyEventLog)
   {
     MyEventLog.Source = Thread.CurrentThread.Name.ToString();
     EventLog.WriteEntry(Thread.CurrentThread.Name.ToString(),
        "Error in Widget 42");
   }
   

请参见

任务

How to: Create and Remove Custom Event Logs

How to: Write Entries to Event Logs

如何：协调多个执行线程

演练：用 Visual Basic 创作简单的多线程组件

演练：使用 Visual C# 创作简单的多线程组件

参考

SyncLock 语句

其他资源

组件中的多线程处理