限制RICHTEXTBOX的输入的范围

 

附件：

http://files.cnblogs.com/xe2011/WindowsFormsApplication_LimitRichTextBoxInput.rar

---

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 WindowsFormsApplication4

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

       

 #region 设置 和 获得光标所在的行号///要在本类中初始化 richTextBox1 = this;private int EM_LINEINDEX = 0x00BB;private int EM_LINEFROMCHAR = 0x00C9;[System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "SendMessage")]public static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);/// <summary>/// 获得光标所在的行号和列号/// </summary>/// <param name="editControl"></param>/// <returns>p.X =列号  p.Y =行号</returns>public Point GetCaretPosition(){int charIndex = (int)SendMessage(richTextBox1.Handle, EM_LINEINDEX, -1, 0);int lineIndex = (int)SendMessage(richTextBox1.Handle, EM_LINEFROMCHAR, charIndex, 0);Point pt = new Point();pt.X = richTextBox1.SelectionStart - charIndex + 1;//Line
pt.Y = lineIndex + 1;//Columnreturn pt;}/// <summary>/// 转到行/// </summary>/// <param name="Line">行号</param>public void jumpLine(int Line){richTextBox1.SelectionStart = SendMessage(richTextBox1.Handle, EM_LINEINDEX, Line - 1, 0);richTextBox1.SelectionLength = 0;richTextBox1.ScrollToCaret();}#endregion

 

        //限制文本的能删除的最小范围

        private int nLimiteLength = 10;

        private void richTextBox1_KeyDown(object sender, KeyEventArgs e)

        {

            //放置跨行选中文本然后输入文字

            if (richTextBox1.SelectedText.IndexOf("\n") != -1)

            {

                Text = "MupltiLineSel";

                e.Handled = true;

            }

            //直接屏蔽的

            //Enter Ctrl+V Ctrl+X DEL

            if (e.KeyData == Keys.Enter ||

                e.KeyData == (Keys.Control|Keys.V)||

                e.KeyData == (Keys.Control|Keys.X)||

　　　　　　　　　 e.KeyData == Keys.Delete　  

　　　　　　)

            {

                Text = "禁止 Enter Ctrl+V Ctrl+X Space";

                e.Handled = true;

            }

            int x = GetCaretPosition().X;

            

            //BACK 

            if (e.KeyData == Keys.Back )

            {

                if (x < nLimiteLength + 1)

                {

                    Text = "禁止 Back";

                    e.Handled = true;

                }

            }

        }

           

        private void richTextBox1_KeyPress(object sender, KeyPressEventArgs e)

        {

            //放置跨行选中文本然后输入文字

            if (richTextBox1.SelectedText.IndexOf("\n") != -1)

            {

                Text = "MupltiLineSel";

                e.Handled = true;

            }

            int x = GetCaretPosition().X;

            if (x < nLimiteLength)

                e.Handled = true;

            //space bar

            if (e.KeyChar == ' ' && x < nLimiteLength)

                e.Handled = true;

        }

        private void timer1_Tick(object sender, EventArgs e)

        {

            Text = String.Format("X={0},Y={1},SelLength={2}", GetCaretPosition().Y, GetCaretPosition().X, richTextBox1.SelectedText.Length);

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            //因为输入汉字能突破上面的限制

            richTextBox1.ImeMode = System.Windows.Forms.ImeMode.Off;

        }

    }

}

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