C#lambda expression Recording

Foundation, you are master, please float away ...

Usually do the project write code rarely use lambda expression, hereby add, record down.

1 What is a lambda expression?

MSDN statement: using a lambda expression, you can write a local function that can be passed as a parameter or returned as a function call value

At first glance, really a bit uncomfortable, Chinese did not learn!!! It's machine-translated, and it's a roar ...

Take an example.

Lambda expression x=>x*x input x, output x*x

If you have one of these methods:

1 public int getX2 (int x) {return x*x;}

Note that there is a difference, how can the expression be the same as the method?

c# method is passed as a parameter! Yes, that's the Commission. For example:

1 Delegate int del (int  i);    2 Static void Main (string[] args)3{4     del mydelegate = x = x * x;< /c15>5     int j = mydelegate (5//j =6 }

2 Lambda type

An expression lambda

The lambda expression that the expression is on the right side of the = = operator is called expression Lambda. The expression lambda returns the result of an expression and takes the following basic form:

(input parameters) = Expression

See Example:

Static void Main (string[] args)        {            int56;            Func<intint int > f = ((x1, y1) = x1 + y1);                      Console.WriteLine (f (x, y). ToString ());            Console.read ();         }

What's the result? 11

Func is a generic delegate that typically comes with a return value.

Statement Lambda

A statement lambda is similar to an expression lambda expression, except that the statement is enclosed in curly braces:

1 (input parameters) = {statement;}

Such as:

1  Static void Main (string[] args)2        {3             action<string> F = (x) = = {Console.WriteLine (x);}; 4             F ("hello,world"); 5             console.read (); 6         }

Where: Action is a non-return value, generic delegate that is provided internally by. Net.

The structure is as follows:

 1  delegate  void   Action ();  2  delegate  void  Action<in  t> (T obj);  3  delegate  void  Action<in  t, (T obj,t1 obj1);  4  delegate  void  Action<in  t,in  t2> (T obj,t1 obj1,t2 obj2); 
 ... 

Just write it down here.

C#lambda expression Recording