Why can I not write MessageBox.Show("asdfasdf{0}", i);?

Question

int i = 85; 
Console.WriteLine("My intelligence quotient is {0}", i);  // Kosher
MessageBox.Show("My intelligence quotient is {0}", i); // Not Kosher

I find this most distressful an debilitating. One works and not the other? What is the source of this behavioural incongruity? The more I think about it the less I can imagine, and failure to understand too often turns to self-loathing.

Answer 1

The Show() method simply has no proper overload.

It was added to Console.WriteLine as matter of convenience, but it's not integral part of every .NET method.

To achieve same effect, use string.Format manually:

MessageBox.Show(string.Format("asdfasdf{0}", i)); // Kosher

Answer 2

Console.Writeline has these overloads:

• http://msdn.microsoft.com/en-us/library/system.console.writeline.aspx

In particular, an overload that accepts a format string and a params array.

Here's another method that is quite similar:

• http://msdn.microsoft.com/en-us/library/system.string.format.aspx

I don't know why MessageBox.Show doesn't have the overload. I'd guess it is because there are already so many other overloads for that method.

But you can get a similar effect by adding string.Format to it:

public void ShowMessageBox(string format, params object[] args)
{
    MessageBox.Show(string.Format(format, args));
}

// ...

ShowMessageBox("You entered: {0}", someValue);

Answer 3

Why is hard to tell (it is just how MS defined it) but IF you want to write "congruent" code for both cases then you can use string.Format - for example like this:

MessageBox.Show (string.Format ("asdfasdf{0}", i));

or

Console.WriteLine (string.Format ("asdfasdf{0}", i)); // although this is unneccesary!