“使用（实体obj =新实体（））”的优点是什么？每次单独上课？ [英] What is the advantage of "Using (Entity obj=new Entity())" every time with in individually in classes?

问题描述

每次在c＃代码中使用此功能有什么好处。

What is advantage of using this in c# code for everytime.

using (Entities ctx = new Entities())
    {
        var rst = from tbl in ctx.TEST_TBL
                  select tbl;
        foreach (var tbl in rst)
        {
            Console.WriteLine(tbl.ID);
        }
    }

推荐答案

使用块做两件事：它会自动调用Dispose对代码退出块时创建的项目 - 出于任何原因 - 并且它仅将变量的范围限制为该cod块：您不能意外地引用Disposed对象，因为编译器一旦它超出范围就会抱怨它不再存在。



你应该总是处理任何实现IDisposable的对象，并且使用块可以轻松方便。

A using block does two things: it automatically calls Dispose on the item created whenever the code exits the block - for any reason at all - and it restricts the scope of the variable to that block of cod only: you cannot accidentally reference a Disposed object because the compiler will complain that it doesn't exist any more once it is out of scope.

You should always Dispose any object that implements IDisposable, and a using block makes that easy and convenient.

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