只能输入数字或字母

 

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e)        {            if ((e.KeyChar >= '0' && e.KeyChar <= '9') || (e.KeyChar >= 'A' && e.KeyChar <= 'F') || (e.KeyChar >= 'a' && e.KeyChar <= 'f') || ((Keys)(e.KeyChar) == Keys.Back))            { e.Handled = false; }            else            {                e.Handled = true;                MessageBox.Show("只能输入数字或字母(A-F[a-f])");            }        }

参考资料：http://zhidao.baidu.com/question/323451912.html