Use of C # using

? preface

Speaking of C # using the statement, presumably everyone is not unfamiliar, it is one of the keywords in C # . We basically write code every day to use, in fact, it is very simple.

1. first of all, tell me what the use of using is .

1) for referencing namespaces in other assemblies , for example:

using System.Collections.Generic;

2) to set an alias for a namespace or class name

1) setting aliases for namespaces

using Gen = System.Collections.Generic;

2) set alias for class name

using intlist = System.Collections.Generic. List < int >;

intlist list = New intlist();

List. ADD (1);

3) Releasing object resources

1) Releasing object resources is also one of the using common usages,C # through the . NET Framework Common Language runtime (CLR) from Memory that is used to store objects that are no longer needed.

2) The Systemmust be implemented with a class that uses a using -free object resource. The IDisposable interface, which completes the release of the resource in the Dispose () method.

2. using Basic usage

First, declare a test class

Public class usingclass : System. IDisposable

{

    public " Span lang= "en-US" style= "font-family:; Color: "> string ObjectName { get ; set ;}

public usingclass (string objname)

    {

this. ObjectName = objname;

    }

public void Dispose ()

    {

Console. WriteLine ("{0} has been destroyed ", ObjectName);

    }

}

s) declaring an object

using (usingclass UC = new usingclass(" Object " ))

{

Console. WriteLine ("using statement execution ");

}

Execution Result:

2) Declare multiple objects at the same time

using (UsingclassUCA =New Usingclass("object A " ), UCB =New Usingclass("object B " ), UCC =New Usingclass("object C " ))

{

Console. WriteLine ("using statement execution ");

}

Execution Result:

3) new object (of course, this usage is of no practical significance)

using (new usingclass(" object "))

{

Console. WriteLine ("using statement execution ");

}

Execution Result:

Use of C # using