C#窗体应用程序的问题

怎样用C#窗体来实现让用户输入两个整数,然后再输入0-3之间的一个数,0代表加法,1代表减法,2代表乘法,3代表除法,计算这两个数字的结果。用switch语句可以吗?


private void button3_Click(object sender, System.EventArgs e)
{
    if (textBox1.Text.Length == 0 || textBox2.Text.Length == 0 || textBox3.Text.Length == 0)
    {
        textBox4.Text = "输入错误!";
        return;
    }

    float a, b, s = 0;
    a = float.Parse(textBox1.Text);
    b = float.Parse(textBox2.Text);
    int c = int.Parse(textBox3.Text);
    switch (c)
    {
        case 0:
            s = a + b;
            break;
        case 1:
            s = a - b;
            break;
        case 2:
            s = a * b;
            break;
        case 3:
            if (b == 0)
            {
                textBox4.Text = "除数为零!";
                return;
            }
            s = a / b;
            break;
        default:
            textBox4.Text = "输入错误!";
            return;

    }
    textBox4.Text = s.ToString();

}

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