c#文本框限制输入内容

 

 

 //限制输入不能为中文和全角

        private void zhbh_KeyPress(object sender, KeyPressEventArgs e)

        {

            int chfrom = Convert .ToInt32("4e00", 16);    //范围（0x4e00～0x9fa5）转换成int（chfrom～chend）

            int chend = Convert .ToInt32("9fa5", 16);

            if (e.KeyChar >= (Char )chfrom && e.KeyChar <= (Char)chend)

            {

                e.Handled = true;

            }

            if (e.KeyChar >= (Char )65281 & (int)e.KeyChar <= ( Char)65374)

            {

                e.Handled = true;

            }

        }

 

//*******以下方法需在文本框的KeyPress方法下调用

        //限制输入只能为数字

        private void wz_qsh_KeyPress(object sender, KeyPressEventArgs e)

        {

            if (!(Char .IsNumber(e.KeyChar)) && e.KeyChar != (Char)8)

            {

                e.Handled = true;

            }

        }

 /**

         * 限制只能输入数字和小数点

         * */

        public void validationOnlyFloat(KeyPressEventArgs e, TextBox t)

        {

            if (((int )e.KeyChar < 48 || (int)e.KeyChar > 57) && ( int)e.KeyChar != 8 && (int )e.KeyChar != 46)

                e.Handled = true;

            //小数点的处理。

            if ((int )e.KeyChar == 46)                           //小数点

            {

                if (t.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(t.Text, out oldf);

                    b2 = float.TryParse(t.Text + e.KeyChar.ToString(), out f);

                    if (b2 == false )

                    {

                        if (b1 == true )

                            e.Handled = true;

                        else

                            e.Handled = false;

                    }

                }

            }

        }