C#完成 使用异步线程定时更新窗体标签内容，并对标签内容进行求和显示

这是我在面试过程中遇到的一个小测试，很可惜，当天未能圆满完成，虽然第二天经过实际测试已经OK 了，但学无止境，继续努力吧，特将此代码贴在这里，供以后学习使用；

 namespace mytest
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         private void button1_Click(object sender, EventArgs e)
         {
             timer1.Interval = ;
             timer1.Enabled = true;

         }

         public delegate void mydelegate( );
         public mydelegate myway;
         public mydelegate myway2;
         private void check(object obj)
         {
             myway();

         }
         private void check2(object obj)
         {
             myway2();

         }
         private void add1( )
         {

                 int i = Convert.ToInt32(label1.Text);
                 i++;
                 if (!this.IsHandleCreated || this.IsDisposed) return;
                 if (InvokeRequired)
                 {
                     this.Invoke((MethodInvoker)delegate
                     {

                         label1.Text = i.ToString();

                     });
                 }
                 else
                 {

                 }

         }

         private void add2()
         {

                 int i = Convert.ToInt32(label2.Text);
                 i++;
                 if (!this.IsHandleCreated || this.IsDisposed) return;
                 if (InvokeRequired)
                 {
                     this.Invoke((MethodInvoker)delegate
                     {

                         label2.Text = i.ToString();

                         int j = Convert.ToInt32(label1.Text);
                         j = j + i;
                         label3.Text = j.ToString();

                     });
                 }
                 else
                 {

                 }

         }

         private void Form1_Load(object sender, EventArgs e)
         {
             myway += new mydelegate(add1);
             myway2 += new mydelegate(add2);
         }

         private void timer1_Tick(object sender, EventArgs e)
         {

             ThreadPool.QueueUserWorkItem(new WaitCallback(check), null);//执行线程池
             ThreadPool.QueueUserWorkItem(new WaitCallback(check2), null);//执行线程池
         }
     }
 }

窗体界面如下: