C＃/ VB.NET using语句实际上对未实现IDisposable的类做任何事情

Question

If i have something like the following:

public class Myclass{

//some resources

}

and then in another class i do the following:

using(Myclass myclass = new Myclass()) {
// do things with myclass instance

}

Does the using statement in this case actually provide any use? Myclass has not implemented the IDisposable interface so there isn't any Dispose() method to call. Am i thinking about this correctly?

Answer 1

If your class is not implementing IDisposable then you can't use it inside using statement. It would be a compile time error.

Other than that, using statement translates into try-finally block and at the end of using statement, Dispose is called (even in case of an exception) . There is nothing magical done by CLR to actually dispose the object, it all depends on the implementation of Dispose . You can have an empty implementation of Dispose method and there will be no effect.

Answer 2

You cannot use using with types that don't implement IDisposable . You will get a compiler error. That's it.

• MSDN C# : ... All such types must implement the IDisposable interface....
• MSDN VB.NET ...Required. The class of the resource. The class must implement the IDisposable interface...

This is the CS1674 compiler error you get.