如何申报接口的事件处理程序？ [英] How to declare an event handler in an interface?

问题描述

我有几个Silverlight 4的用户界面对象（导航页更喜欢它）有实现两件事情：OnError事件处理程序，并刷新（）方法。

I have a few Silverlight 4 UI objects (Navigation Pages more like it) that have to implement two things: OnError event handler, and Refresh() method.

于是，我尝试了以下内容：

So I tried the following:

public interface IDynamicUI
{
    event EventHandler<ErrorEventArgs> OnError;
    void Refresh();
}

public class ErrorEventArgs : EventArgs
{
    public string Message { get; set; }
    public Exception Error { get; set; }
}

但是编译器给我的错误说字段不能公开的接口中声明

but the compiler gives me errors saying that fields cannot be declared inside public interfaces.

好，问题是，都应该实现这个页面被托管导航框架内，采用SL4导航框架。这是罚款和花花公子不过，我也需要能够中继子页面（如错误）内发生的事件给父页面。更过我希望能够迫使基于发生在父事件子页面UI的刷新。

Well the problem is that the pages that are supposed to implement this are hosted inside a navigation frame, employing the SL4 navigation framework. That is fine and dandy however, I also need to be able to relay events that happen within the child page (like errors) to the parent page. More over I wanted to be able to force a refresh of child pages UI based on events that occur in the parent.

要规避使用反射（看什么类型在导航面板中显示的页）我想只提取IDynamic UI出来。这将让我做这样的事情：

To circumvent using reflection (to see what is the Type of the page displayed in the navigation panel) I wanted to just extract the IDynamic UI out of it. This would allow me to do something like this:

public class ParentPage : Page
{
    IDynamicUI selectedUI = null;

    //fires when the ChildContent frame loads a child page...
    private void ChildContentFrame_Navigated(object sender, NavigationEventArgs e)
    {
        object childPage = ChildContentFrame.Content;
        this.selectedUI = (IDynamicUI)childPage;
        this.selectedUI.OnError += new EventHandler(ChildPage_OnError);
    }

    private void ChildPage_OnError(object sender, ErrorEventArgs e)
    {
        //do my error handling here.
    }
}

对于所有你们谁是MVVM / MVC的球迷......嗯，这是不是。我知道，如果一个MVVM apprach被带到使得这款，它会一直轻松了很多，但应用程序已经写，我不打算从头开始重写。 （

For all of you who are fans of MVVM/MVC... well this is not it. I do know that if an MVVM apprach was taken into making this, it would've been a lot easier, however the app was already written and I am not going to rewrite it from scratch. :(

由于
马丁

推荐答案

尝试定义为事件动作< ErrorEventArgs>的OnError;

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