如何利用C# timer控件实现查看当前系统时间

 1 using System;
 2 using System.Windows.Forms;
 3 
 4 namespace EXP3_53_GetTime
 5 {
 6     public partial class Form1 : Form
 7     {
 8         
 9         public Form1()
10         {
11             InitializeComponent();
12         }
13         bool flag = false;
14         private void button1_Click(object sender, EventArgs e)
15         {
16             flag = true;
17         }
18 
19         private void timer1_Tick(object sender, EventArgs e)
20         {
21             if (flag)
22             {
23                 DateTime time = DateTime.Now;
24                 label1.Text = "当前系统时间为：" + time.ToString();
25             }
26         }
27     }
28 }