全角转半角

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar > 65280 && e.KeyChar < 65375 )
            {
                e.KeyChar = (char)(e.KeyChar - 65248);
            }

            if (e.KeyChar == 12288)
            {
                e.KeyChar = (char)32;
            }

        }