Question

I’m fairly new to C# programming.

I am making a program for fun that adds two numbers together, than displays the sum in a message box. I have two numericUpDowns and a button on my form. When the button is pushed I want it to display a message box with the answer.

The problem is, I am unsure how to add the twp values from the numericUpDowns together.

So far, I have this in my button event handler:

private void button1_Click(object sender, EventArgs e)     {         MessageBox.Show(this.numericUpDown1.Value + this.numericUpDown2.Value);     } 

But obviously, it does not work. It gives me 2 compiler errors: 1. The best overloaded method match for ‘System.Windows.Forms.MessageBox.Show(string) has some invalid arguments 2. Argument ‘1’: cannot convert decimal to ‘string’

Thanks!

Answer 1

this.numericUpDown1.Value + this.numericUpDown2.Value is actually evaluating properly to a number, so you’re actually very close. The problem is that the MessageBox.Show() function, needs a string as an argument, and you’re giving it a number.

To convert the result to a string, add .ToString() to it. Like:

private void button1_Click(object sender, EventArgs e)     {         MessageBox.Show((this.numericUpDown1.Value + this.numericUpDown2.Value).ToString());     } 

For reference, if you want to do more advanced formatting, you’d want to use String.Format() instead of ToString(). See this page for more info on how to use String.Format().