用ASCII码来判断
if(textbox1.Text.Trim()!="")
{
int cd=comboBox5.Text.Trim().Length;
for( int cd1=0;cd1<=cd-1;cd1++)
{
ASCIIEncoding asc=new ASCIIEncoding();
byte[] asc1=asc.GetBytes(textBox1.Text[cd1].ToString());
string aaa=asc1[0].ToString();
if(int.Parse(asc1[0].ToString())>57 | (int.Parse(asc1[0].ToString())<48 &int.Parse(asc1[0].ToString())!=46))//数字的ASCII码为48~57,小数点的ASCII为46
{
MessageBox.Show("IP中不能含有除数值及小数点以外的其他字符,请重新输入!","含有非法字符",MessageBoxButtons.OK,MessageBoxIcon.Error );
textBox1.Focus();
textBox1.SelectAll();
return;
}
}
}
if(textbox1.Text.Trim()!="")
{
int cd=comboBox5.Text.Trim().Length;
for( int cd1=0;cd1<=cd-1;cd1++)
{
ASCIIEncoding asc=new ASCIIEncoding();
byte[] asc1=asc.GetBytes(textBox1.Text[cd1].ToString());
string aaa=asc1[0].ToString();
if(int.Parse(asc1[0].ToString())>57 | (int.Parse(asc1[0].ToString())<48 &int.Parse(asc1[0].ToString())!=46))//数字的ASCII码为48~57,小数点的ASCII为46
{
MessageBox.Show("IP中不能含有除数值及小数点以外的其他字符,请重新输入!","含有非法字符",MessageBoxButtons.OK,MessageBoxIcon.Error );
textBox1.Focus();
textBox1.SelectAll();
return;
}
}
}
把这段程序放到你的textBox1的KeyUp 事件中就可以了,这样每次输入一个字符都进行验证