incorrect output from Debug.WriteLine("Put text here: {0}", myString)

Question

String.Format works fine with Debug.WriteLine if variable not of string type:

int myNumber = 1;
Debug.WriteLine("Put number here: {0}", myNumber);

Correct Output with Non-String

• Put number here: 1

But if variable is string:

string myString = "ShouldWork";
Debug.WriteLine("Put text here: {0}", myString);

Incorrect Output with String

• ShouldWork: Put text here: {0}

Why?

Answer 1

You are getting the wrong overload...

You could work around that:

Debug.WriteLine("Put text here: {0}", myString, null/*dummy*/);

A good wrapper would be

public static void DebugFormat(string fmt, params object[] p)
{
     Debug.WriteLine(fmt, p); // this will select the right overload 
                              // ... due to typeof(p)==object[]
}

// ...
DebugFormat("Put text here: {0}", myString, null/*dummy*/);
int myNumber = 1;
DebugFormat("Put number here: {0}", myNumber);

Answer 2

You are inadvertently calling a different overload:

http://msdn.microsoft.com/en-us/library/1w33ay0x.aspx

For the desired behavior, you can use string concatenation:

Debug.WriteLine("Put text here: " + myString);

or a call to String.Format:

Debug.WriteLine(String.Format ("Put text here: {0}", myString));

Answer 3

Try:

Debug.WriteLine(string.Format("Put number here: {0}", 1));

Also, make sure that your Output option (drop down menu) in Visual Studio is set to Debug... It is not on by default in many cases.