I'm getting an unhandled exception on my Add program

[357mag]

This program inputs two integers and then the user can choose to Add them or Subtract them. I'm using a Visual C# book by Joyce Farrell. But when I run the program I'm getting an unhandled exception error.

Unable to cast object of type "System.Windows.Forms.Textbox to type System.Convertible.

My code is this:

 private void buttonAdd_Click(object sender, EventArgs e)
        {
            int firstNumber;
            int secondNumber;
            int sum;

            firstNumber = Convert.ToInt32(textBoxFirstNumber);
            secondNumber = Convert.ToInt32(textBoxSecondNumber);

            sum = firstNumber + secondNumber;

            labelAnswer.Text = "The sum is " + sum;
        }

 

[357mag]

I fixed it. I keep forgetting the .text at the end of Convert.ToInt32(textBoxfirstNumber)

I keep forgetting that last part needs to be (textBoxFirstNumber.Text)

 

[357mag]

There is something I spotted in my code that baffles me:

 private void buttonSubtract_Click(object sender, EventArgs e)
        {
            int firstNumber;
            int secondNumber;
            int difference;

            firstNumber = Convert.ToInt32(textBoxFirstNumber.Text);
            secondNumber = Convert.ToInt32(textBoxSecondNumber.Text);
        }

My variables are firstNumber and secondNumber. But Visual Studio insists that I use textBoxSecondNumber or textBoxFirstNumber. The capitalization is different. The drop-down menu even shows that next to the text I'm writing in the editor.

I don't get that.

 

[Skydiver]

Welcome to the forum. In the future please put your code in code tags. Easiest way to do that is to use the icon on the toolbar that looks like </>

 

[Skydiver]

Anyway VS is just making a guess as to what you may want to do. It's not really insisting. You can turn off IntelliSense and the code suggestions of it annoys you.

 

[cjard]

I keep forgetting the .text at the end of Convert

Use a NumericUpDown