将自定义 EventArgs 作为事件参数传递

Question

我是事件的新手，一直在尝试创建一个并成功，但我有一个问题。

我创建了这样的事件：

public class CustomControl : Panel
{
    public event EventHandler OutputChanged; //My event

    public CustomControl()
    {
        InitializeComponents();            
    }

    //This event raises inside richtextbox which is inside my panel
    private void OnTextChanged(object sender, EventArgs e)
    {
        if (OutputUpdate == OutputUpdate.OnTextChanged)
        {
            ValidateText();
            //This is my created event
            OnOutputChanged(new OutputChangedEventArgs { Asd = "Something" });
        }
    }

    //void for this event
    protected virtual void OnOutputChanged(OutputChangedEventArgs e)
    {
        EventHandler handler = OutputChanged;
        if(handler != null)
        {
            handler(this, e);
        }
    }
}

//Custom event args class for my event
public class OutputChangedEventArgs : EventArgs
{
    public string Asd { get; set; }
}

上面的代码显示了我的事件的声明和EventArgs参数的自定义类，现在我将向您展示我如何在我的代码中实现它：

customControl1.OutputChanged += OnOutputChanged;

private void OnOutputChanged(object sender, EventArgs e)
{
    OutputChangedEventArgs args = e as OutputChangedEventArgs;
    MessageBox.Show(args.Asd);
}

正如你在我的植入中看到的那样，我通过了EventArgs，然后我将其转换为OutputChangedEventArgs，原因是因为如果我尝试private void OnOutputChanged(object sender, OutputChangedEventArgs e)我会出错No overload for 'OnOutputChanged' matches delegate 'EventHandler'

所以我的问题是如何直接传递我的自定义EventArgs类，这样我就不需要在处理它的方法中转换它？

Answer 1

您可以使用EventHandler允许指定参数类型的通用版本。

public event EventHandler<OutputChangedEventArgs> OutputChanged;