如何在 C# 中不使用单击事件（按钮）来计算总数？

Question

I'm doing a simple calculator using C# and I already made it work when I press a button, like this.

private void button1_Click(object sender, EventArgs e)
       {
           int a = int.Parse(textBox1.Text);
           int b = int.Parse(textBox2.Text);

           if (comboBox1.Text == "+")
               textBox3.Text = (a + b).ToString();

           if (comboBox1.Text == "-") 
               textBox3.Text = (a - b).ToString();

           if (comboBox1.Text == "*")
               textBox3.Text = (a * b).ToString();

           if (comboBox1.Text == "/") 
               textBox3.Text = (a / b).ToString();
       }

What I'm trying to do is for the result in textBox3 to change as I choose the operator from the comboBox without having to press a button. I've tried using the Leave event with no success. Any help will be appreciated.

Answer 1

您可以连接到 SelectedIndexChange 事件

Answer 2

private void combobox1_textChanged(object sender, EventArgs e)
{
   int a = int.Parse(textBox1.Text);
       int b = int.Parse(textBox2.Text);

       if (comboBox1.Text == "+")
           textBox3.Text = (a + b).ToString();

       if (comboBox1.Text == "-") 
           textBox3.Text = (a - b).ToString();

       if (comboBox1.Text == "*")
           textBox3.Text = (a * b).ToString();

       if (comboBox1.Text == "/") 
           textBox3.Text = (a / b).ToString();
}

The above is pseduo code, but just add the "textChanged" event and put the code inside like shown above.