不要嵌套类型警告(C#)

我在类中有以下代码来设置串行端口甚至处理程序.

我得到两个警告; CA1034(不要窝类型),它告诉我,使我delgate私人(这将阻止我是来设置,甚至处理在继承的类),以及CA1009(申报事件的第二个参数作为一个EventArgs,或一个实例一个扩展EventArgs的类型,名为'e'),我不明白.

我的代码如下

myPort.DataReceived += new SerialDataReceivedEventHandler(port_OnDataRecived); //Setup when port is opened

private void port_OnDataRecived(object sender, SerialDataReceivedEventArgs e)
{
        int lengthToRead = myPort.BytesToRead;
        byte[] rxBytes = new byte[lengthToRead];
        myPort.Read(rxBytes, 0, lengthToRead);
        PacketReceived(rxBytes, e);
}

public delegate void PacketReceivedEventHandler(object sender, byte[] packet);
public event PacketReceivedEventHandler OnPacketReceived;

public virtual void PacketReceived(byte[] packet, EventArgs e)
{
        if (OnPacketReceived != null)
        {
            OnPacketReceived(this, packet);                
        }
}

我一直在查看MSDN文章和一些SO问题,但我无法将建议的修复程序与我自己的代码联系起来. 这个答案是有道理的,但转换我的代码看起来像它导致

OnPacketReceived(this, packet); 

被替换为

handle(this, new PacketReceivedEventHandler();

这是一个争论(void (object, byte[]) target)(这是我被困的地方).至于尝试修复CA1034警告,我甚至看不到我写的是嵌套类型,MSDN文章没有包含如何修复规则违规的示例.

我甚至不知道我写的是嵌套类型

您已PacketReceivedEventHandler在类中声明了委托类型().这是嵌套在另一个内部的一种类型.只需将声明移到现有的类声明之外.

对于另一个警告,您需要创建一个PacketEventArgs派生自EventArgs并包含数据包数据的类作为额外属性.此时,您可以使用an EventHandler而不是声明自己的委托.

另外:

您当前检查处理程序无效的方法已被破坏,因为它可能会在调用之间从非null变为null.

通常会调用事件PacketReceived并且您的方法将被OnPacketReceived(并受到保护),而不是相反.

有了这一切,你就拥有:

public event EventHandler PacketReceived;

protected virtual void OnPacketReceived(byte[] packet)
{
    var handler = PacketReceived;
    if (handler != null)
    {
        handler.Invoke(this, new PacketEventArgs(packet));
    }
}

或者在C#6中,使用null条件运算符使实现更简单:

public event EventHandler PacketReceived;

protected virtual void OnPacketReceived(byte[] packet)
{
    PacketReceived?.Invoke(this, new PacketEventArgs(packet));
}