有沒有辦法可以批量註冊活動？

Question

我有許多母類，每個類都有不同數量的相同類型的子對象。母親班需要向所有這些孩子對象註冊一個事件。

想知道是否有任何好方法自動進行註冊？

類似於：遍歷母類中的所有屬性，查找子類型的屬性以及註冊事件。

Answer 1

您可以使用反射來訂閱事件。

定義子類：

class Child { 
     public Child() { }    

     // Define event 
     public event EventHandler DidSomethingNaughty; 

     // Proeprty used to trigger event 
     public bool IsNaughty { 
      get { return this.isNaughty; } 
      set { 
       this.isNaughty = value; 
       if (this.IsNaughty) { 
        if (this.DidSomethingNaughty != null) { 
         this.DidSomethingNaughty(this, new EventArgs()); 
        } 
       } 
      } 
     } 

     // Private data member for property 
     private bool isNaughty = false; 
    } 

定義媽媽級：

class Mother { 

     public Mother() { 
      this.subscribeToChildEvent(); 
     } 

     // Properties 
     public Child Child1 { 
      get { return this.child1; } 
      set { this.child1 = value; } 
     } 

     public Child Child2 { 
      get { return this.child1; } 
      set { this.child2 = value; } 
     } 

     public Child Child3 { 
      get { return this.child3; } 
      set { this.child3 = value; } 
     } 

     public Child Child4 { 
      get { return this.child4; } 
      set { this.child4 = value; } 
     } 

     // Private data members for the properties 
     private Child child1 = new Child(); 
     private Child child2 = new Child(); 
     private Child child3 = new Child(); 
     private Child child4 = new Child(); 

     // This uses reflection to get the properties find those of type child 
     // and subscribe to the DidSomethingNaughty event for each 
     private void subscribeToChildEvent() { 
      System.Reflection.PropertyInfo[] properties = 
       typeof(Mother).GetProperties(); 
      foreach (System.Reflection.PropertyInfo pi in properties) { 
       if (pi.ToString().StartsWith("Child")) { 
        Child child = pi.GetValue(this, null) as Child; 
        child.DidSomethingNaughty += 
         new EventHandler(child_DidSomethingNaughty); 
       } 
      } 
     } 

     private void child_DidSomethingNaughty(object sender, EventArgs e){ 
      Child child = (Child)sender; 
      if (child.IsNaughty) { 
       this.discipline(child); 
      } 
     } 

     private void discipline(Child child) {     
      MessageBox.Show("Someone was naughty"); 
      // reset the flag so the next time the childe is 
      //naughty the event will raise 
      child.IsNaughty = false; 
     } 
    } 

然後初始化一個母親的對象，它會下標事件：

Mother m = new Mother(); 

然後設置IsNaughty Child1屬性爲true：

m.Child1.IsNaughty = true; 

你應該得到一個消息框：

資源：

https://stackoverflow.com/a/737156/1967692

https://stackoverflow.com/a/3179869/1967692