.NET c# - 如何将附加数据传递给 PropertyChangedEventHandler

Question

我有这个代码：

public void SomeMethod() 
{
    MyClass clss = new MyClass();    //note: MyClass implements INotifyPropertyChanged
    clss.DoSomething();
    clss.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(MyEventHandler);
}
static void MyEventHandler(object sender, System.ComponentModel.PropertyChangedEventArgs e) 
{
    Debug.WriteLine("some property on MyClass has changed!");
}

这工作正常，当 SomeClass 中的属性更改时，MyEventHandler() 为运行。但是现在我需要将附加数据从 SomeMethod() 传递到 MyEventHandler() ，我该怎么做？

* 更新 *

好的，我想我应该更好地解释整个问题：MyClass 中的方法 DoSomething() 调用外部 Web 服务，向其传递回调，以便当 Web 服务完成其工作，它将调用回调，将操作结果传递给它一个值。在该回调中，我正在更改 class 的属性以为其分配从 Web 服务接收到的值，从而触发 propertyChanged 事件。然后在调用者 class 中，我订阅了那个事件，这样我就可以在它发生时做一些事情。

最后的 objective 是，在调用 DoSomething() 之后，能够等到 Web 服务完成其工作并 returned 结果，这样我就可以保存一些数据库中的东西等等，只有这样，return 来自 SomeMethod()...

所以这是 MyClass，简化版：

public class MyClass : INotifyPropertyChanged
{
    private long _wsReturnValue;
    public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;
    public long wsReturnValue 
    {
        get { return _wsReturnValue; }
        set {
            _wsReturnValue = value;
            OnPropertyChanged("wsReturnValue");
        }
    }
    protected void OnPropertyChanged(string name) 
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) 
            handler(this, new System.ComponentModel.PropertyChangedEventArgs(name));
    } 

    public void DoSomething(object entity) 
    {
        //here I just call external web service and returns, the webservice will call TheCallback() when finished
    }

    public void TheCallback(CommunicationEventArgs e) 
    {
        this.wsReturnValue = e.res;
    }

}

这是使用 MyClass 的 class：

class MainClass
{
    public void SomeMethod(object someObject)
    {
        MyClass clss = new MyClass();    //note: MyClass implements INotifyPropertyChanged
        clss.DoSomething(someObject);   //someObject contains data that I want to use later in the event handler
        clss.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(MyEventHandler);
    }

    private static void MyEventHandler(object sender, System.ComponentModel.PropertyChangedEventArgs e)
    {
        //here I need to use the object someObject...
    }
}

Answer 1

不确定这是否接近您的意思，但是您可以了；

class EventClass
    {
        public void SomeMethod()
        {
            MyClass clss = new MyClass();    //note: MyClass implements INotifyPropertyChanged
            clss.DoSomething(new object());
            clss.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(MyEventHandler);
        }

        private static void MyEventHandler(object sender, System.ComponentModel.PropertyChangedEventArgs e)
        {
            var customeEventArgs = (CustomEventArgs) e;
            Debug.WriteLine("some property on MyClass has changed! Extra Data : {0}", customeEventArgs.ExtraData);
        }
    }

实现了更多shell代码来说明

internal class MyClass
    {
        public void DoSomething(object data)
        {

            var e = new CustomEventArgs("Property")
            {
                ExtraData = data
            };

            PropertyChanged?.Invoke(this, e);
        }

        public event PropertyChangedEventHandler PropertyChanged;


    }

internal class CustomEventArgs : PropertyChangedEventArgs
    {
        public CustomEventArgs(string propertyName) : base(propertyName)
        {
        }

        public object ExtraData { get; set; }
    }

有什么帮助吗？ :)

.NET c# - 如何将附加数据传递给 PropertyChangedEventHandler

.NET c# - how to pass aditional data to PropertyChangedEventHandler

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