C# Message Box, variable usage

Question

I have searched but I dont know if I am using the correct verbiage to search for. I am writing a program in C# for my class but I am having trouble with the message box.

I am trying to have the message box show a message and read a variable at the same time. I have no problem doing this in the console applications but I cannot figure it out for the Windows side.

So far I have:

MessageBox.Show("You are right, it only took you {0} guesses!!!", "Results", MessageBoxButtons.OK);

Which works fine. Howerver I am trying to have the {0} be the result of the variable numGuesses. I'm sure this is simple and I am just overlooking it in the book or something, or I have the syntax incorrect someplace.

`MessageBox.Show(String.Format("You are right, it only took you {0} guesses!!!", numGuesses), "Results", MessageBoxButtons.OK);` — Tim Schmelter, Aug 20 '11 at 22:19

score 15 · Accepted Answer · answered Aug 20 '11 at 22:18

15

try

MessageBox.Show(string.Format ("You are right, it only took you {0} guesses!!!", numGuesses ), "Results", MessageBoxButtons.OK);

see http://msdn.microsoft.com/en-us/library/system.string.format(v=VS.100).aspx

answered Aug 20 '11 at 22:18

Yahia

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Evan Mulawski · Answer 2 · 2011-08-20T22:30:44.913

4

You can use String.Format or simple string concatenation.

MessageBox.Show(String.Format("You are right, it only took you {0} guesses!!!", myVariable), "Results", MessageBoxButtons.OK);

http://msdn.microsoft.com/en-us/library/system.string.format(v=VS.100).aspx

Concatenation:

MessageBox.Show("You are right, it only took you " + myVariable + " guesses!!!", "Results", MessageBoxButtons.OK);

Both results are equivalent, but you may prefer String.Format if you have multiple variables in the same string.

edited Aug 20 '11 at 22:30

answered Aug 20 '11 at 22:18

Evan Mulawski

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I wouldn't say they are equivalent. The format call uses stringbuilder while the concat creates strings (potentially slower). – anthony sottile Aug 20 '11 at 22:29
@Anthony Sottile: Correct. I should have stated that the results are equivalent. – Evan Mulawski Aug 20 '11 at 22:30

score 1 · Answer 3 · answered Aug 20 '11 at 22:18

1

What about String.Format() ?

MessageBox.Show(String.Format("You are right, it only took you {0} guesses!!!", numGuesses), "Results", MessageBoxButtons.OK);

answered Aug 20 '11 at 22:18

Dalmas

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score 1 · Answer 4 · answered Aug 20 '11 at 22:18

1

String.Format is what you want:

string message = string.Format("You are right, it only took you {0} guesses!!!",numGuesses)

MessageBox.Show(message, "Results", MessageBoxButtons.OK);

answered Aug 20 '11 at 22:18

Joe

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score 1 · Answer 5 · answered Aug 20 '11 at 22:18

MessageBox.Show(
                  string.Format(
                                 "You are right, it only took you {0} guesses!!!",
                                Results
                               ), 
                  MessageBoxButtons.OK
               );

score 0 · Answer 6 · answered Oct 29 '20 at 03:31

You are well done with your class, and this thread is old. With that said, today you can solve this issue as such:

var firstName = "Sam";
MessageBox.Show($"My first name is { firstName }.", "First Name", MessageBoxButtons.Ok);

You can also use it in a catch block:

...
}
catch (Exception ex)
{
    MessageBox.Show($"Program encountered an error \n\n{ ex.Message }", "Program Error", MessageBoxButtons.Ok);
}

Basically any string variable can be used in this way. Not sure about functions that return a string, though I don't see why not.

C# Message Box, variable usage

6 Answers6