WINFORM学习手册——Mdi应用（编辑菜单）

一、打开上一章的项目：

二、打开ChildForm，更改RichTextBox的Modifiers属性为internal

三、双击菜单项，完成菜单项的单击事件：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Mdi
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 创建子窗体
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void newToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ChildForm childForm = new ChildForm();
            childForm.MdiParent = this;
            childForm.Show();
        }
        /// <summary>
        /// 层叠布局
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void cascadeToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.LayoutMdi(MdiLayout.Cascade);
        }
        /// <summary>
        /// 横向布局            
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void theHorizontallyToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.LayoutMdi(MdiLayout.TileHorizontal);
        }
        /// <summary>
        /// 竖向布局
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void theVerticallyToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.LayoutMdi(MdiLayout.TileVertical);
        }
        /// <summary>
        /// 上一步
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void undoToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.ActiveMdiChild != null)
            {
                var childForm = (ChildForm)this.ActiveMdiChild;
                childForm.richTextBox1.Undo();
            }
        }
        /// <summary>
        /// 下一步
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void redoToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.ActiveMdiChild != null)
            {
                var childForm = (ChildForm)this.ActiveMdiChild;
                childForm.richTextBox1.Redo();
            }
        }
        /// <summary>
        /// 剪切
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void cutToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.ActiveMdiChild != null)
            {
                var childForm = (ChildForm)this.ActiveMdiChild;
                childForm.richTextBox1.Cut();
            }
        }
        /// <summary>
        /// 复制
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void copyToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.ActiveMdiChild != null)
            {
                var childForm = (ChildForm)this.ActiveMdiChild;
                childForm.richTextBox1.Copy();
            }
        }
        /// <summary>
        /// 粘贴
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void pasteToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (this.ActiveMdiChild != null)
            {
                var childForm = (ChildForm)this.ActiveMdiChild;
                childForm.richTextBox1.Paste();
            }
        }
    }
}