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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