How do I pass line number to a method

Question

In Visual Stuido 2013, working in C# (.Net 4.5), how can I pass a line number to a method call. I recall in C there was a #pragma lineNumber to do this, but searching on those terms brings up nothing.

I want to write a method something like this:

// unchecked code:
private void printResetStopwatch(int lineNumber)
{
   stopwatch.stop();
   System.Console.WriteLine(stopwatch.Elapsed.ToString() + " at line " + lineNumber.ToString();
}

and I would call it something like

printResetStopwatch(#pragma lineNumber);

if #pragma was the answer.

Answer 1

The way to do this is to attribute a parameter on the method with the CallerLineNumberAttribute and provide it with a default value. C# will then fill it in with the line number of the caller

void Method(string message, [CallerLineNumber] int lineNumber = 0) { 
  ...
}

Method("foo");  // C# will insert the line number here 

Note that there are actually a set of related attributes here that might interest you. Here is a sample

public void TraceMessage(string message,
        [CallerMemberName] string memberName = "",
        [CallerFilePath] string sourceFilePath = "",
        [CallerLineNumber] int sourceLineNumber = 0)

Full Documentation: http://msdn.microsoft.com/en-us/library/hh534540.aspx

Note: This requires the C# 5.0 compiler which is included in VS 2013.