这是我重写的一个TextBox控件，希望对你有用
/**********************************************************************
* Created by : Sunny.li
* Create Date: 2007/11/09
* Description:
* Samples :
*
**********************************************************************/
using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace MyApp
{
public class NumberBox : System.Windows.Forms.TextBox
{
public NumberBox()
{
this.TextAlign = HorizontalAlignment.Right;
}
public enum NumberType
{
intNumber,
DecimalNumber
}
private NumberType numberType = NumberType.intNumber;
/// <summary>
/// get or set the Number Type
/// </summary>
public NumberType Numbertype
{
get
{
return numberType;
}
set
{
numberType = value;
}
}
private int iNumberLength = 10;
/// <summary>
/// get or set the integral' length of Number
/// </summary>
public int INumberLength
{
set
{
iNumberLength = value;
}
get
{
return iNumberLength;
}
}
protected override void OnKeyPress(KeyPressEventArgs e)
{
base.OnKeyPress(e);
if (numberType == NumberType.intNumber)
{
if (IsNum(e.KeyChar))
e.Handled = false;//允许输出
else
e.Handled = true;//禁止输出
}
else
{
if (IsDecimal(e.KeyChar))
e.Handled = false;//允许输出
else
e.Handled = true;//禁止输出
}
}
private bool IsNum(char keyChar)
{
if (((keyChar >= 48 && keyChar <= 57)) || keyChar == 8)
{
if (this.Text.Trim().Length <= iNumberLength-1)
return true;
else
return false;
}
else
return false;
}
private bool IsDecimal(char keyChar)
{
if (((keyChar >= 48 && keyChar <= 57)) || keyChar == 8 || keyChar == 46)
{
if (this.Text.Trim().LastIndexOf('.') <= iNumberLength)
{
if (this.Text.Trim().Contains(".") && keyChar == 46)
return false;
else
return true;
}
else
{
if (keyChar != 8)
{
return false;
}
return true;
}
}
else
return false;
}
}
}