小例子（二）、winform窗体间的关系

1     　　 //登陆窗体 
2     　　 private void button2_Click(object sender, EventArgs e)
3         {
4             Form2 fr = new Form2();
5             this.Visible = false;//隐藏窗体
6             fr.Show();
7         }

1    　　 //注册一个关闭时结束程序的事件，FormClosing
2         private void Form2_FormClosing(object sender, System.Windows.Forms.FormClosingEventArgs e)
3         {
4             Application.Exit();//结束整个程序
5         }

1      public static class Class1
2     {
3         public static Form3 f3;//存form3
4     }

1         private void Form3_Load(object sender, EventArgs e)
2         {
3             Class1.f3 = this;//将form3的对象放在class类中
4         }

1         private void button4_Click(object sender, EventArgs e)
2         {
3             Class1.f3.Close();//关闭Form3
4         }

1         private void button2_Click(object sender, EventArgs e)
2         {
3             Class1.f4.Close();//先关闭form4
4             Form4 fr = new Form4();
5             fr.Show();//再打开form4
6         }