如何：创建池对象并设置其大小和超时限制

对于从 System.EnterpriseServices.ServicedComponent 类派生的类，可以使用 COM+ 对象池来避免从头实例化对象的开销。COM+ 对象池不是从头开始实例化对象，而是在激活时从池中提取对象。有关详细信息，请参阅对象池。

创建池对象并设置其大小和超时限制

1. 定义一个从 System.EnterpriseServices.ServicedComponent 类派生的类，并将 ObjectPoolingAttribute 属性应用于该类。例如，以下代码定义一个名为 TestObjectPooling 的类并为该类设置 MinPoolSize、MaxPoolSize 和 CreationTimeout 属性。

   <ObjectPooling(MinPoolSize := 2, MaxPoolSize := 5, _
   CreationTimeout := 20000)> _
   Public Class TestObjectPooling 
   Inherits ServicedComponent
   End Class 
   

   [ObjectPooling(Enabled=true, MinPoolSize=2, MaxPoolSize=5, CreationTimeout=20000)]
   public class TestObjectPooling : ServicedComponent
   {
   }
   

2. 重写 System.EnterpriseServices.ServicedComponent 类的 Activate、Deactivate 和 CanBePooled 方法。

3. 在客户端应用程序中测试池对象：

   1. 创建池对象类的一个实例并对池对象调用这些方法。例如，以下代码创建 TestObjectPooling 类的一个实例并调用 Perform 方法。

      Public Class App
          Overloads Public Shared Sub Main(args() As String)
             Dim order As New TestObjectPooling()
                  order.Perform()
      
      

      public class App
      {
          public static int Main(string[] args)
          {
             TestObjectPooling order = new TestObjectPooling();
             order.Perform();
      
      

   2. 调用 DisposeObject 方法，将对象返回到池中。

      ServicedComponent.DisposeObject (order)
      

      ServicedComponent.DisposeObject (order);
      

示例

<ObjectPooling(MinPoolSize := 2, MaxPoolSize := 5, _
CreationTimeout := 20000)> _
Public Class TestObjectPooling 
Inherits ServicedComponent
      Public Sub Perform ()
            ' Method contents go here.
      End Sub 
      Protected Overrides Sub Activate()
            ' Called when removed from the pool.
      End Sub 
      Protected Overrides Sub Deactivate()
            ' Called before deactivating or placing back in pool.
      End Sub 
      Protected Overrides Function CanBePooled() As Boolean
            ' Called after Deactivate. Indicate your vote here.
            Return True
      End Function 
End Class 

[ObjectPooling(Enabled=true, MinPoolSize=2, MaxPoolSize=5, CreationTimeout=20000)]
public class TestObjectPooling : ServicedComponent
{
      public void Perform ()
      {
         // Method contents go here.
      }
      protected override void Activate()
      {
         // Called when removed from the pool.
      }
      protected override void Deactivate()
      {
         // Called before deactivating or placing back in pool.
      }
      protected override bool CanBePooled()
      {
         // Called after Deactivate. Indicate your vote here.
         return true;
      }
}
 

请参见

参考

ObjectPoolingAttribute
System.EnterpriseServices Namespace

概念

可用的 COM+ 服务摘要
对象池

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