Regex 例

密码复杂度:数字英文符号
Regex r = new Regex("^(?:(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])|(?=.*[A-Z])(?=.*[a-z])(?=.*[^A-Za-z0-9])|(?=.*[A-Z])(?=.*[0-9])(?=.*[^A-Za-z0-9])|(?=.*[a-z])(?=.*[0-9])(?=.*[^A-Za-z0-9])).{6,}|(?:(?=.*[A-Z])(?=.*[a-z])|(?=.*[A-Z])(?=.*[0-9])|(?=.*[A-Z])(?=.*[^A-Za-z0-9])|(?=.*[a-z])(?=.*[0-9])|(?=.*[a-z])(?=.*[^A-Za-z0-9])|(?=.*[0-9])(?=.*[^A-Za-z0-9])|).{6,}");

var regex = new Regex(@"
(?=.*[0-9])                     #必须包含数字
(?=.*[a-zA-Z])                  #必须包含小写或大写字母
(?=([x21-x7e]+)[^a-zA-Z0-9])  #必须包含特殊符号
.{8,30}                         #至少8个字符，最多30个字符
", RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace);