C#的多文档界面（MDI）

首先：创建父窗体 设置IsMdiContainer属性为true。

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace UsingMDI{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void visualC2010ToolStripMenuItem_Click(object sender, EventArgs e)        {            Form child1 = new Form();            child1.MdiParent = this;            child1.Text = "窗体0";            child1.Show();        }        private void visualC2010ToolStripMenuItem1_Click(object sender, EventArgs e)        {            Form child2 = new Form();            child2.MdiParent = this;            child2.Text = "窗体1";            child2.Show();        }        private void cascadeToolStripMenuItem_Click(object sender, EventArgs e)        {            this.LayoutMdi(MdiLayout.Cascade);        }        private void visualBasic2010ToolStripMenuItem_Click(object sender, EventArgs e)        {            Form child2 = new Form();            child2.MdiParent = this;            child2.Text = "窗体2";            child2.Show();        }        private void tileHorizontalToolStripMenuItem_Click(object sender, EventArgs e)        {            this.LayoutMdi(MdiLayout.TileHorizontal);        }        private void tileVerticalToolStripMenuItem_Click(object sender, EventArgs e)        {            this.LayoutMdi(MdiLayout.TileVertical);        }        private void exitToolStripMenuItem_Click(object sender, EventArgs e)        {            Application.Exit();        }    }}