c# – 如何向webform项目添加回调

我想为对象的所有方法添加一个通用的回调函数.我找到了 this SO question,但在那个方法中,我将不得不修改该类的每个功能.我想定义一些在每个方法调用之前得到trigered的beforeFilter方法.我知道我可以使用 Action delegates,但我不知道如何.

更新：作为一个例子,我想要的是这样的

Class MyClass

    Sub MyCallback
        'callback code...
    End Sub

    'Rest of tyhe code

End Class

正如您所看到的,理想情况是在所有其他方法之前添加一个简单(或多个)方法来进行三重处理.也许有一些基类或接口,我不知道(这就是我要求的原因).

我认为可能有的其他选项是克隆对象并定义一个新类,而不是将代码添加到现有类中.因此,在该类中使用Object来访问类型的方法

Class NewClass

     Sub AddCallback(Obj As Object,Callback As Action)
          'Add the callback here
     End Sub
End Class

我只是猜测,也许我的一些选择甚至是不可行的,所以请帮助我

解决方法

以下是代理如何工作以及如何使用它们的示例：

public class MyClass
{
    // MyDelegate callback holder
    private MyDelegate _myDelegate;

    // Singleton holder
    private static volatile MyClass _instance;

    ///<summary>
    /// Instance property
    ///</summary>
    public static MyClass Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = new MyClass();
            }
            _instance.MyCallbacks(_instance.MyDelegateCallback,_instance.MyDelegateCallback1);
            return _instance;
        }
    }

    ///<summary>
    /// Instance multi-callback caller
    ///</summary>
    ///<param name="callbacks">calbacks to call</param>
    ///<returns>MyClass</returns>
    public static MyClass Instance(params MyDelegate[] callbacks)
    {
        if (_instance == null)
        {
            _instance = new MyClass();
        }
        _instance.MyCallbacks(callbacks);
        return _instance;
    }

    ///<summary>
    /// MyClass constructor
    ///</summary>
    private MyClass()
    {
        // Define the callback
        MyDelegate = MyDelegateCallback;
    }

    ///<summary>
    /// MyDelegate property,here u can change the callback to any function which matches the structure of MyDelegate 
    ///</summary>
    public MyDelegate MyDelegate
    {
        get
        {
            return _myDelegate;
        }
        set
        {
            _myDelegate = value;
        }
    }

    ///<summary>
    /// Call all given callbacks
    ///</summary>
    ///<param name="callbacks">callbacks u want to call</param>
    public void MyCallbacks(params MyDelegate[] callbacks)
    {
        if (callbacks != null)
        {
            foreach (MyDelegate callback in callbacks)
            {
                if (callback != null)
                {
                    callback.Invoke(null);
                }
            }
        }
    }

    ///<summary>
    /// RunTest,if u call this method the defined callback will be raised
    ///</summary>
    public void RunTest()
    {
        if (_myDelegate != null)
        {
            _myDelegate.Invoke("test");
        }
    }

    ///<summary>
    /// MyDelegateCallback,the callback we want to raise
    ///</summary>
    ///<param name="obj"></param>
    private void MyDelegateCallback(object obj)
    {
        System.Windows.MessageBox.Show("Delegate callback called!");
    }

    ///<summary>
    /// MyDelegateCallback1,the callback we want to raise
    ///</summary>
    ///<param name="obj"></param>
    private void MyDelegateCallback1(object obj)
    {
        System.Windows.MessageBox.Show("Delegate callback (1) called!");
    }
}

///<summary>
/// MyDelegate,the delegate function
///</summary>
///<param name="obj"></param>
public delegate void MyDelegate(object obj);

我更新了我的答案,看看MyCallbacks(params MyDelegate []回调).它将调用与MyDelegate.Edit结构相匹配的不同回调：添加了MyClass.Instance& MyClass.Instance(params MyDelegate []回调).

c# – 如何向webform项目添加回调

解决方法

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