1     public partial class 标签页 : Form
 2     {
 3         string s = "";
 4         public 标签页()
 5         {
 6             InitializeComponent();
 7         }
 8         /// <summary>
 9         /// 判断选项卡中是否有本选项卡
10         /// </summary>
11         /// <param name="s">选项卡名</param>
12         /// <returns>布尔型</returns>
13 
14         private bool HasTablePages(string s)
15         {
16             for (int i = 0; i < tabControl1.TabPages.Count; i++)
17             {
18                 if (tabControl1.TabPages[i].Text == s)
19                 {
20                     tabControl1.SelectedIndex = i;//如果选项卡中有本选项卡，则把本选项卡设为焦点
21                     return false;
22                 }
23             }
24             return true;
25         }
26         /// <summary>
27         /// 点击菜单时，创建本选项卡，同时将自定义的选项卡控件添加进去
28         /// </summary>
29         /// <param name="s">选项卡名</param>
30         /// <param name="uc">自定义的控件</param>
31         private void MenuAdd(string s,UserControl uc)
32         {
33             if (HasTablePages(s))
34             {
35                 TabPage page = new TabPage();
36                 page.Text = s;
37 
38                 page.Controls.Clear();
39                 page.Controls.Add(uc);
40                 uc.Dock = DockStyle.Fill;
41 
42                 tabControl1.TabPages.Add(page);
43                 tabControl1.SelectedTab = page;
44             }
45         }
46         private void 会员管理ToolStripMenuItem_Click(object sender, EventArgs e)
47         {
48             s = "会员管理";
49             UC_HuiYuan uc = new UC_HuiYuan();
50             MenuAdd(s,uc);
51         }
52 
53         private void 数据管理ToolStripMenuItem_Click(object sender, EventArgs e)
54         {
55             s = "数据管理";
56             UC_ShuJu sj = new UC_ShuJu();
57             MenuAdd(s,sj);
58         }
59 
60         private void 客房管理ToolStripMenuItem_Click(object sender, EventArgs e)
61         {
62             s = "客房管理";
63             UC_KeFang kf = new UC_KeFang();
64             MenuAdd(s,kf);
65         }
66         /// <summary>
67         /// 双击选项卡名时，关闭本选项卡
68         /// </summary>
69         /// <param name="sender"></param>
70         /// <param name="e"></param>
71         private void tabControl1_DoubleClick(object sender, EventArgs e)
72         {
73             tabControl1.TabPages.RemoveAt(tabControl1.SelectedIndex);
74         }
75     }

 1     public partial class Form1 : Form
 2     {
 3         public Form1()
 4         {
 5             InitializeComponent();
 6         }
 7         /// <summary>
 8         /// 关闭所有窗口
 9         /// </summary>
10         /// <param name="sender"></param>
11         /// <param name="e"></param>
12         private void 关闭所有窗口ToolStripMenuItem_Click(object sender, EventArgs e)
13         {
14             while (this.MdiChildren.Length > 0)
15             {
16                 MdiChildren[0].Close();
17             }
18         }
19         /// <summary>
20         /// 新建Form2
21         /// </summary>
22         /// <param name="sender"></param>
23         /// <param name="e"></param>
24         private void ToolStripMenuItem_Click(object sender, EventArgs e)
25         {
26             bool b = true;//用来判断子窗口中是否存在Form2
27             for (int i = 0; i < this.MdiChildren.Length; i++)
28             {
29                 if (this.MdiChildren[i].Name == "Form2")
30                 {
31                     b = false;
32                 }
33             }
34             //没有子窗口 或者 子窗口中没有Form2 时
35             if (this.MdiChildren.Length == 0 || b)
36             {
37                 Form2 fm = new Form2();
38                 fm.MdiParent = this;
39                 fm.Show();
40             }
41         }
42         /// <summary>
43         /// 新建Form3
44         /// </summary>
45         /// <param name="sender"></param>
46         /// <param name="e"></param>
47         private void toolStripMenuItem2_Click(object sender, EventArgs e)
48         {
49             bool b = true;
50             for (int i = 0; i < this.MdiChildren.Length; i++)
51             {
52                 if (this.MdiChildren[i].Name == "Form3")
53                 {
54                     b = false;
55                 }
56             }
57             if (this.MdiChildren.Length == 0||b)
58             {
59                 Form3 fm = new Form3();
60                 fm.MdiParent = this;
61                 fm.Show();
62             }
63         }
64     }