我有以下事件,我班级的消费者可以连接以获取内部诊断消息.
public event EventHandler<string> OutputRaised;
我用这个函数引发事件
protected virtual void OnWriteText(string e)
{
var handle = this.OutputRaised;
if (handle != null)
{
var message = string.Format("({0}) : {1}",this.Port,e);
handle(this,message);
}
}
为什么我正确获取CA1009声明事件处理程序？我找到的所有答案似乎都不适用于我的场景……只是想了解,我还没有真正掌握事件和代表.
参考CA1009：http://msdn.microsoft.com/en-us/library/ms182133.aspx
解决方法
根据’规则’,EventHandler的type-parameter应该从EventArgs继承：
Event handler methods take two parameters. The first is of type
System.Object and is named ‘sender’. This is the object that raised
the event. @H_502_20@The second parameter is of type System.EventArgs and is
named ‘e’. This is the data that is associated with the event. For
example,if the event is raised whenever a file is opened,the event
data typically contains the name of the file.
在你的情况下,这可能是这样的：
public class StringEventArgs : EventArgs
{
public string Message {get;private set;}
public StringEventArgs (string message)
{
this.Message = message;
}
}
和你的事件处理程序：
public event EventHandler<StringEventArgs> OutputRaised;
当你举起事件时,你应该创建一个StringEventArgs类的实例：
protected virtual void OnWriteText( string message )
{
var handle = this.OutputRaised;
if (handle != null)
{
var message = string.Format("({0}) : {1}",e);
handle(this,new StringEventArgs(message));
}
}
我还想补充一点,从理论上讲,你的代码没有任何问题.编译器不会抱怨,您的代码也会起作用. EventHandler< T>委托未指定type参数应从EventArgs继承.它是FxCop,表示您违反了用于声明事件的“设计规则”.
