[C#]重写文本控件的OnKeyPress和OnTextChanged进行录入数据校验

//记录OnKeyPress前的字符  string BeforKeyPressText = "";  //记录OnKeyPress执行时输入被视为无效（e.Handled = true;）的次数 注：一个汉字和一个英文字母的输入各执行一次OnKeyPress  int ErrKeyPressNum = 0;  /// <summary>  /// 实现输入控制：字符过滤  /// by arming 2005-11-28  /// </summary>  /// <param name="e"></param>  protected override void OnKeyPress(KeyPressEventArgs e)  {   //取出击键前的文本框文本   BeforKeyPressText = this.Text;

   string[] regexExpressions=new string[2];   regexExpressions= (string[])CommonDataDefine.HtDTRE()[this.InputType.ToString()];   Regex regex = new Regex(regexExpressions[0]);   Match m = regex.Match(e.KeyChar.ToString());   if(!m.Success)   {    e.Handled = true;    //被处理为无效输入    ++ErrKeyPressNum;   }

   base.OnKeyPress (e);  }

  /// <summary>  ///   /// </summary>  /// <param name="e"></param>  protected override void OnTextChanged(EventArgs e)  {   if( ErrKeyPressNum > 1 )   {    --ErrKeyPressNum;    return;   }   if( ErrKeyPressNum == 1 )   {    --ErrKeyPressNum;    this.Text = BeforKeyPressText;    this.Select(BeforKeyPressText.Length,0);   }         if(this.InputType.ToString()=="Decimal4"&&this.Text.Trim()!=""&&this.Text.Trim()!="-")   {    try    {     decimal inputDecimal = System.Convert.ToDecimal(this.Text.Trim());     //数字长度     int p = this.MaxLength;     //小数点位置     int d1 = BeforKeyPressText.IndexOf('.');     int d2 = this.Text.Trim().IndexOf('.');     //     if(d2==-1&&this.Text.Trim().Length>p-4)     {      this.Text = BeforKeyPressText;      this.Select(BeforKeyPressText.Length,0);     }     else if(d2!=-1&&(this.Text.Trim().Length-d2-1>4||d2>p-4))     {      this.Text = BeforKeyPressText;      this.Select(BeforKeyPressText.Length,0);     }    }    catch    {     this.Text = BeforKeyPressText;     this.Select(BeforKeyPressText.Length,0);    }   }   //整数 判断输入是否大于或小于Int所能保存的数值范围   if((this.InputType.ToString()=="Number"||this.InputType.ToString()=="Int")&&this.Text.Trim()!=""&&this.Text.Trim()!="-")   {    try    {     int inputNum = System.Convert.ToInt32(this.Text.Trim());    }    catch    {     this.Text = BeforKeyPressText;     this.Select(BeforKeyPressText.Length,0);    }   }   //有两位小数点的小数 如Decimal(12,2)    if(this.InputType.ToString()=="Decimal"&&this.Text.Trim()!=""&&this.Text.Trim()!="-")   {    try    {     decimal inputDecimal = System.Convert.ToDecimal(this.Text.Trim());     //数字长度     int p = this.MaxLength;     //小数点位置     int d1 = BeforKeyPressText.IndexOf('.');     int d2 = this.Text.Trim().IndexOf('.');          if(d2==-1&&this.Text.Trim().Length>p-2)     {      this.Text = BeforKeyPressText;      this.Select(BeforKeyPressText.Length,0);     }     else if(d2!=-1&&(this.Text.Trim().Length-d2-1>2||d2>p-2))     {      this.Text = BeforKeyPressText;      this.Select(BeforKeyPressText.Length,0);     }    }    catch    {     this.Text = BeforKeyPressText;     this.Select(BeforKeyPressText.Length,0);    }   }      base.OnTextChanged (e);  }