设置文本框只能输入数字型字符串

 #region  设置文本框只能输入数字型字符串

        /// <summary>

        /// 文本框只能输入数字型和单精度型的字符串.

        /// </summary>

        /// <param name="e">KeyPressEventArgs类</param>

        /// <param name="s">文本框的字符串</param>

        /// <param name="n">标识，判断是数字型还是单精度型</param>

        public void Estimate_Key(KeyPressEventArgs e,string s,int n)

        {

            if (n==0)   //只能输入整型

                if (!(e.KeyChar <= '9' && e.KeyChar >= '0') && e.KeyChar != '\r' && e.KeyChar != '\b')

                {

                    e.Handled = true;   //处理KeyPress事件

                }

            if (n == 1) //可以输入整型或单精度型

            {

                if ((!(e.KeyChar <= '9' && e.KeyChar >= '0')) && e.KeyChar != '.' && e.KeyChar != '\r' && e.KeyChar != '\b')

                {

                    e.Handled = true;

                }

                else

                {

                    if (e.KeyChar == '.')   //如果输入“.”

                        if (s == "")    //当前文本框为空

                            e.Handled = true;   //处理KeyPress事件

                        else

                        {

                            if (s.Length > 0)   //当文本框不为空时

                            {

                                if (s.IndexOf(".") > -1)    //查找是否已输入过“.”

                                    e.Handled = true;   //处理KeyPress事件

                            }

                        }

                }

            }

        }

        #endregion