C#委托全写在一个窗体里还是委托么

C#委托全写在一个窗体里还是委托么

double first, second;
        string input;
        bool sfcz = false;
        delegate double ProcessDelegate(double param1,double param2);

        private double add(double param1, double param2)
        {
            return param1 + param2;
        }

        private double del(double param1, double param2)
        {
            return param1 - param2;
        }

        private double Multiply(double param1, double param2)
        {
            return param1 * param2;
        }

        private double Divide(double param1, double param2)
        {
            return param1 / param2;
        }

        //数字1按钮事件 其他数字类似 不多写了
        private void button1_Click(object sender, EventArgs e)
        {
            if (sfcz)
            {
                sfcz = false;
                textBox1.Text = "";
            }
            textBox1.Text += "1";
        }

        //加号按钮事件 其他减乘除类似 不多写了
        private void button11_Click(object sender, EventArgs e)
        {
            if (textBox1.Text.Trim() != "")
            {
                sfcz = true;
            }
            first = Convert.ToDouble(textBox1.Text);
            input = "加";
        }

//等号按钮事件
 private void button15_Click(object sender, EventArgs e)
        {
            second = Convert.ToDouble(textBox1.Text);
            ProcessDelegate process;
            if (input == "加")
            {
                process = new ProcessDelegate(add);
            }
            else if (input == "减")
            {
                process = new ProcessDelegate(del);
            }
            else if (input == "乘")
            {
                process = new ProcessDelegate(Multiply);
            }
            else if (input == "除")
            {
                process = new ProcessDelegate(Divide);
            }
            else
            {
                //textBox1.Text = "请选择操作符";
                MessageBox.Show("请选择操作符");
                return;
            }
            textBox1.Text = process(first, second).ToString();
        }

算，但是你这么做属于多此一举。为了演示委托的妙处，给你的代码修改下：
private void button15_Click(object sender, EventArgs e)
         {
             second = Convert.ToDouble(textBox1.Text);
             Dictionary<string, ProcessDelegate> dict = new Dictionary<string, ProcessDelegate>();
             dict.Add("加", new ProcessDelegate(add));
             dict.Add("减", new ProcessDelegate(del));
             dict.Add("乘", new ProcessDelegate(Multiply));
             dict.Add("除", new ProcessDelegate(Divide));
             if (!dict.HasKey(input))
             {
                 //textBox1.Text = "请选择操作符";
                 MessageBox.Show("请选择操作符");
                 return;
             }
             textBox1.Text = dict[input](first, second).ToString();
         }