Group Dispatcher.Invoke in the same function

Question

如何分組若干Dispatcher.Invoke並在運行以下組之前等待一個組完成？

以下面爲例，第一組創建兩個併發運行的線程。兩個線程完成後，第二組線程開始，等等。

private void FooMethod() 
{ 
    // First group 
    dispatcher.Invoke(new FooDelegate(Foo), cmd1A); 
    dispatcher.Invoke(new FooDelegate(Foo), cmd1B); 

    // Second group 
    dispatcher.Invoke(new FooDelegate(Foo), cmd2A); 
    dispatcher.Invoke(new FooDelegate(Foo), cmd2B); 

    // Third group 
    dispatcher.Invoke(new FooDelegate(Foo), cmd3A); 
    dispatcher.Invoke(new FooDelegate(Foo), cmd3B); 

    .... 
} 

Answer 1

你可以在帶有隊列的分派器周圍創建一個包裝類來處理組。代碼可以是凌亂的，但它應該提供的總體思路：

public class DispatcherGroup 
{ 
    private List<Action> _delegates; 
    private List<object[]> _parameters; 
    private ManualResetEvent _isFinished; 

    public void Add(Action toInvoke, params object[] parameters) 
    { 
     _delegates.Add(toInvoke); 
     _parameters.Add(parameters); 
    } 

    public void Invoke(Dispatcher dispatcher) 
    { 
     List<DispatcherOperation> operations = new List<>(); 
     for(int i = 0; i < _delegates.Length; i++) 
     { 
      DispatcherOperation operation = dispatcher.BeginInvoke(_delegates[i], _parameters[i]); 
      operations.Add(operation); 
     } 

     // check status of all operations before completion 
    } 

} 

public class DispatcherGroupInvoker 
{ 
    private Queue<DispatcherGroup> _groups; 
    public Dispatcher Dispatcher { get;set;} 
    public void Invoke() 
    { 
     while (!_groups.Count != 0) 
     { 
      DispatcherGroup group = _groups.Dequeue(); 
      group.Invoke(Dispatcher); 
     } 
    } 
}