CODEWITHSUNDEEP
c#winforms
mason22
mason22

Reputation: 35

Adding numbers using button to a textbox

I'm new to programming and I have a problem. I have two buttons and a textbox. When I press the button, a number will show on the textbox, but when I press the second button the number in the textbox overwrites it and replaces it instead of adding to it in the textbox. How do I fix this? I want the values to add instead of replacing it.

public partial class Form1 : Form
{
    int value1 = 0;
    int value2 = 0;
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        value1++;
        textBox1.Text = value1.ToString();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        value2 += 2;
        textBox1.Text = value2.ToString();
    }
}

}

Upvotes: 1

Views: 4473

Answers (3)

Dmitrii Bychenko
Dmitrii Bychenko

Reputation: 186668

If you want to add two integers and assign the result back to textBox1 you have to

  1. Parse textBox1.Text to integer: int.Parse(textBox1.Text)
  2. Sum up values: int.Parse(textBox1.Text) + value2
  3. Convert the outcome back to string: (...).ToString()

Implementation:

private void button2_Click(object sender, EventArgs e) { 
  value2 += 2;

  textBox1.Text = (int.Parse(textBox1.Text) + value2).ToString();
}

Edit: If there's a possibility that textBox1.Text doesn't contain a valid integer value (say, textBox1.Text is empty) you can use int.TryParse:

private void button2_Click(object sender, EventArgs e) { 
  if (int.TryParse(textBox1.Text, out var v)) {
    value2 += 2;
    textBox1.Text = (v + value2).ToString();
  }
  else {
    //TODO: textBox1.Text is not a valid integer; put relevant code here 
  } 
}

Upvotes: 4

whatthefish
whatthefish

Reputation: 347

Add this line:

textBox1.Text = (int.parseInt(textBox1.Text) + value2).toString();

after

value2 += 2;

into your button2_click method:

Upvotes: 0

redsoxfantom
redsoxfantom

Reputation: 956

You're using two separate variables (value1 and value2 above) to store the results of each button click, depending in which button was clicked. Think of it like this:

On program start:
value1 = 0
value2 = 0

User clicks button 1, which executes button1_Click. This increments value1 (via value1++), so the two variables look like this:

value1 = 1
value2 = 0

User then clicks button 2, which executes button2_Click. This sets value2 to whatever was previously in value2 + 2. However, note that the value of value1 is unchanged:

value1 = 1
value2 = 2

By having separate variables, each button click is operating on a different value. I would modify your code so there is only one value variable that both _Click functions modify.

Upvotes: 0

Related Questions