C#中设置textbox限制条件的方法

本文实例讲述了c#中设置textbox限制条件的方法，分享给大家供大家参考。具体实现方法如下：

#region 设置数量等textbox控件样式及限制条件（具体调用的方法就是重写或直接调用shieldnumbertextboxotherkeys函数）

/// <summary>
/// 屏蔽数字textbox的其他字符串
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
public virtual void tboxnumbers_keydown(object sender, keyeventargs e)
{
    e.suppresskeypress = true;

    switch (e.keycode)
    {
 case keys.d0:
 case keys.d1:
 case keys.d2:
 case keys.d3:
 case keys.d4:
 case keys.d5:
 case keys.d6:
 case keys.d7:
 case keys.d8:
 case keys.d9:
 case keys.numpad0:
 case keys.numpad1:
 case keys.numpad2:
 case keys.numpad3:
 case keys.numpad4:
 case keys.numpad5:
 case keys.numpad6:
 case keys.numpad7:
 case keys.numpad8:
 case keys.numpad9:
 case keys.back:
 case keys.oemperiod:
 case keys.delete:
 case keys.decimal:
     e.suppresskeypress = false;
     break;
 default:
     break;
    }
}

public virtual void tboxnumbers_keypress(object sender, keypresseventargs e)
{
    textbox tbox = sender as textbox;
    char c = e.keychar;

    if (c.tostring().equals("."))
    {
 if (tbox.text.length <= 0)
     e.handled = true;           //小数点不能在第一位    
 else
 {
     float f;
     float oldf;
     bool b1 = false, b2 = false;
     b1 = float.tryparse(tbox.text, out oldf);
     b2 = float.tryparse(tbox.text + e.keychar.tostring(), out f);
     if (b2 == false)
     {
  if (b1 == true)
      e.handled = true;
  else
      e.handled = false;
     }
 }
    }
}

/// <summary>
/// 屏蔽数字textbox的其他字符串
/// </summary>
/// <param name="tbox">要屏蔽的textbox</param>
public virtual void shieldnumbertextboxotherkeys(textbox tbox)
{
    tbox.imemode = imemode.disable;
    tbox.keydown += tboxnumbers_keydown;
    tbox.keypress += tboxnumbers_keypress;
}

#endregion

希望本文所述对大家的c#程序设计有所帮助。