什么是符号QUOT; = GT;"我在这个C＃代码方法后做什么？

问题描述：

最近，我在这里问一个问题，有人提供了这样的回答：

I recently asked a question here, and someone provided this answer:

private void button1_Click(object sender, EventArgs e)
{
     var client = new WebClient();
     Uri X = new Uri("http://www.google.com");

     client.DownloadStringCompleted += (s, args) => //THIS, WHAT IS IT DOING?
     {
         if (args.Error == null && !args.Cancelled)
         {
             MessageBox.Show();
         }
     };

     client.DownloadStringAsync(X);
}

什么是=>在做什么？这是我第一次看到这一点。

What is that => doing? It's the first time I'm seeing this.

答

基本上它说：我给你这个 （S，b），你正在返回取值* b 我什么，如果你正在使用的lambda用表情，但它可以是东西是这样的：我给你这个（S，b）并与他们做的东西像语句块：

Basically it says "I am giving you this (s,b)" and you are returning me s*b or something and if you are using lambda with expressions, but it can be something like this : I am giving you this (s,b) and do something with them in the statement block like :

{
  int k = a+b;
  k = Math.Blah(k);
  return k;
}

~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

一个 LAMBDA 表情写在地方委托实例的一位不愿透露姓名的方法。编译器立即lambda表达式转换为两种：

A Lambda expression is an unnamed method written in place of a delegate instance. The compiler immediately converts the lambda expression to either :

一个委托实例

的表达式树

委托INT变压器（int i）以

class Test{
  static void Main(){
     Transformer square = x => x*x;
     Console.WriteLine(square(3));
  } 

}

我们可以重写它像这样：

We could rewrite it like this :

委托INT变压器（int i）以

class Test{
  static void Main(){
     Transformer square = Square;
     Console.WriteLine(square(3));
  } 
  static int Square (int x) {return x*x;}
}

一个lambda表达式有以下形式：

A lambda expression has the following form :

（参数）=&GT;表达式或语句块

在前面的例子中有一个参数， X ，而表达的是 X * X

In previous example there was a single parameter,x, and the expression is x*x

在我们的例子中，x对应参数i，表达式 X * X 对应的返回类型 INT ，因此是与变压器的委托兼容;

in our example, x corresponds to parameter i, and the expression x*x corresponds to the return type int, therefore being compatible with Transformer delegate;

委托INT变压器（int i）以

一个lambda表达式的代码可以是一个语句块而不是表达。我们可以重写我们的例子如下：

A lambda expression's code can be a statement block instead of an expression. We can rewrite our example as follows :

x => {return x*x;}

这是表达式树，类型表达式来; T&GT; ，表示在穿越的对象模型的LAMDA表达式中的代码。这允许lambda表达式稍后在运行时（请检查LINQ查询表达式）intrepreted

An expression tree, of type Expression<T>, representing the code inside the lamda expression in a traversable object model. This allows the lambda expression to be intrepreted later at runtime (Please check the "Query Expression" for LINQ)

什么是符号QUOT; = GT;"我在这个C＃代码方法后做什么？

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