代表可以有一个可选参数吗? [英] Can a Delegate have an optional parameter?

问题描述

在我尝试添加 bool NetworkAvailable = true 部分之前，我的以下代码运行良好.现在我在下面的第 4 行得到 Method name expected 编译时异常.

I have the below code that was working fine until I tried adding the bool NetworkAvailable = true portion. Now I get a Method name expected compile time exception at Line 4 below.

void NetworkStatus_AvailabilityChanged(object sender, NetworkStatusChangedArgs e)
{
   var networkAvailable = e.IsAvailable;
   SetUpdateHUDConnectedMode d = new SetUpdateHUDConnectedMode(UpdateHUDConnectedMode(networkAvailable));
   this.Invoke(d);
}   

delegate void SetUpdateHUDConnectedMode(bool NetworkAvailable = true);
private void UpdateHUDConnectedMode(bool NetworkAvailable = true)
{
   ...
}

诚然，我是 Delegates 和 Optional Parameters 的新手，因此我将不胜感激.谢谢.

I am, admittedly, new to Delegates and Optional Parameters so I would be grateful for any insight. Thanks.

推荐答案

委托指向方法定义.
实例化指向方法的委托时，不能指定任何参数.

A delegate points to a method definition.
When you instantiate a delegate pointing to a method, you cannot specify any parameters.

相反，您需要将参数值传递给 Invoke 方法，如下所示:

Instead, you need to pass the parameter values to the Invoke method, like this:

SetUpdateHUDConnectedMode d = UpdateHUDConnectedMode;
this.Invoke(d, e.IsAvailable);

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