why we use nested using statement in c#?

Question

using (StreamReader outFile = new StreamReader(outputFile.OpenRead())) 
{    
   StreamReader resFile = new StreamReader(resultFile.OpenRead())    
   {       //Some Codes    }
}

Why does the above resFile object not close automatically?

I wrote the resFile object inside the using statement also. Please explain the using statement.

Answer 1

You didn't use nested using. There's only one using statement.

An example of nested using:

using (...)
{
     using (...)
     {
         ...
     }
}

The reason why you may want to use nested using is that you have more than one declaration that need to be disposed.