c# - 将委托(delegate)分配给采用 N 个参数但未显式声明参数的函数

Question

给定一个带有 N 个参数的函数，为什么可以为其分配一个未显式声明任何参数的委托(delegate)？例如

Func<int, string, object, string, bool> test;
// (1) this makes sense to me
test= delegate (int a, string b, object c, string d) { return true; };

// (2) this also makes sense to me
test= (a,b,c,d)=>true; 

// (3) why does this work? 
test = delegate { return true; }; 

为什么 (3) 有效？ (1)、(2)、(3)之间有什么区别吗？我们可以从第三个变体的大括号内访问参数吗？

Answer 1

Why does (3) work?

来自C# programming guide on MSDN :

Anonymous methods enable you to omit the parameter list. This means that an anonymous method can be converted to delegates with a variety of signatures

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Is there any difference between (1), (2), and (3)?

delegate keyword vs. lambda notation

Can we access the parameters from inside the braces of the third variation?

没有。如果您打算在匿名方法中使用参数，请不要省略参数列表。