需要的正则表达式来验证用户名

Question

需要一个正则表达式来验证用户名，其中：

1. 应该允许尾随空格，但不是空格字符之间
2. 必须至少包含一个字母，可以包含字母和数字
3. 7-15字元（字母数字）
4. 不能包含特殊字符
5. 下划线允许

不知道如何做到这一点。任何帮助表示赞赏。谢谢。

这是我用的是什么，但它可以让人物之间的空间

"(?=.*[a-zA-Z])[a-zA-Z0-9_]{1}[_a-zA-Z0-9\\s]{6,14}" 

示例：用户名 不允许有空格的用户名

Answer 1

试试这个：

foundMatch = Regex.IsMatch(subjectString, @"^(?=.*[a-z])\w{7,15}\s*$", RegexOptions.IgnoreCase); 

是也允许使用_，因为您在尝试时允许这样做。

所以基本上我使用三条规则。一个用于检查是否存在至少一个字母。 另一个检查字符串是否只包含alpha和_，最后我接受尾随空格，并且至少有7个最大值为15个alpha。你的轨道很好。坚持下去，你会在这里也可以回答问题:)

击穿：

" 
^   # Assert position at the beginning of the string 
(?=   # Assert that the regex below can be matched, starting at this position (positive lookahead) 
    .  # Match any single character that is not a line break character 
     *  # Between zero and unlimited times, as many times as possible, giving back as needed (greedy) 
    [a-z] # Match a single character in the range between “a” and “z” 
) 
\w   # Match a single character that is a “word character” (letters, digits, etc.) 
    {7,15} # Between 7 and 15 times, as many times as possible, giving back as needed (greedy) 
\s   # Match a single character that is a “whitespace character” (spaces, tabs, line breaks, etc.) 
    *  # Between zero and unlimited times, as many times as possible, giving back as needed (greedy) 
$   # Assert position at the end of the string (or before the line break at the end of the string, if any) 
"