验证IP

System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex(@"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");            if (!r.IsMatch(tbServer.Text.Trim()))            {                MessageBox.Show("IP格式错误，请重新输入！", "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                tbServer.Focus();                return false;            }

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