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);