为什么.NET代理不能被声明为静态的？ [英] Why can a .NET delegate not be declared static?

问题描述

当我尝试编译以下内容时：

  public static delegate void MoveDelegate（Actor sender，MoveDirection args）; 
  

我收到，作为一个错误：modifer'static'对此项无效。 。

我在一个单例中实现这个，有一个单独的类调用委托。问题是，当我使用其他类中的单例实例调用委托（从标识符，而不是类型），我不能这样做，无论什么原因，即使我声明委托非静态。显然，我只能通过类型直接引用它，如果且仅当委托是静态的。

这是什么推理？我使用MonoDevelop 2.4.2。

更新

建议使用以下代码：

  public void Move（MoveDirection moveDir）
 {
 ProcessMove ）; 
} 
 
 public void ProcessMove（MoveDirection moveDir）
 {
 Teleporter.MoveMethod mm = new Teleporter.MoveMethod（Move）; 
 moveDelegate（this，moveDir）; 
} 
  

我收到一个处理错误，声明MoveMethod必须是

$ p> public delegate void MoveDelegate（object o）;
public static MoveDelegate MoveMethod;


所以方法变量可以定义为static。关键字 static 对于委托定义没有意义，就像 enum 或 const 定义。

如何分配静态方法字段的示例：

  public class A 
 {
 public delegate void MoveDelegate（object o）; 
 public static MoveDelegate MoveMethod; 
} 
 
 public class B 
 {
 public static void MoveIt（object o）
 {
 //做某事
 } 
} 
 
 public class C 
 {
 public void Assign（）
 {
 A.MoveMethod = B.MoveIt; 
} 
 
 public void DoSomething（）
 {
 if（A.MoveMethod！= null）
 A.MoveMethod（new object（））; 
} 
} 
  

When I try to compile the following:

public static delegate void MoveDelegate (Actor sender, MoveDirection args);

I receive, as an error: "The modifer 'static' is not valid for the this item."

I'm implementing this within a singleton, with a separate class which calls the delegate. The problem is that when I use the singleton instance within the other class to call the delegate (from the identifier, not the type), I can't do that for whatever reason, even when I declare the delegate non-static. Obviously, I can only refer to it via the type directly if and only if the delegate is static.

What is the reasoning behind this? I am using MonoDevelop 2.4.2.

update

After trying one of the suggestions with the following code:

public void Move(MoveDirection moveDir)
{
    ProcessMove(moveDir);
}

public void ProcessMove(MoveDirection moveDir)
{
    Teleporter.MoveMethod mm = new Teleporter.MoveMethod(Move); 
    moveDelegate(this, moveDir);
}

I've received a processing error, which states that the MoveMethod must be a type, and not an identifier.

解决方案

Try this:

public delegate void MoveDelegate(object o);
public static MoveDelegate MoveMethod;

So the method-variable can be defined static. The keyword static has no meaning for the delegate definition , just like enum or const definitions.

An example of how to assign the static method-field:

public class A
{
  public delegate void MoveDelegate(object o);
  public static MoveDelegate MoveMethod;
}

public class B
{
  public static void MoveIt(object o)
  {
    // Do something
  }    
}

public class C
{
  public void Assign()
  {
    A.MoveMethod = B.MoveIt;
  }

  public void DoSomething()
  {
    if (A.MoveMethod!=null)
      A.MoveMethod(new object()); 
  }
}

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