C# "Using" Syntax

Question

Does the using catch the exception or throw it? i.e.

using (StreamReader rdr = File.OpenText("file.txt"))
{
 //do stuff
}

If the streamreader throws an exception is it caught by using or thrown so the calling function can handle it?

Answer 1

When you see a using statement, think of this code:

StreadReader rdr = null;
try
{
    rdr = File.OpenText("file.txt");
    //do stuff
}
finally
{
    if (rdr != null)
        rdr.Dispose();
}

So the real answer is that it doesn't do anything with the exception thrown in the body of the using block. It doesn't handle it or rethrow it.