正则表达式分隔逗号分隔符值由双引号括起来

Question

这是我倾向于实现的示例输入和输出格式。我有几个解决方案在网上与正则表达式分开工作，但并不满足所有条件。希望有人能帮忙。我需要一个正则表达式分解解决方案。请不要建议图书馆。谢谢。

List<string> values = new List<string>(); 
Regex lineSplit = new Regex("(?:^|,)(\"(?:[^\"]+|\"\")*\"|[^,]*)", RegexOptions.Compiled); 
foreach (Match match in lineSplit.Matches(line)) 
{ 
    values.Add(match.Value.TrimStart(',').Replace("\"", "")); 
} 

---

"123","456","789" 
123 
456 
789 

"123"","456","789" 
123" 
456 
789 

"123"2","456","789" 
123"2 
456 
789 

"123",2","456","789" 
123",2 
456 
789 

"123","2","456","789" 
123 
2 
456 
789 

Answer 1

如果非正则表达式的方法也被认为是，我建议摆脱初始和结尾的引号的（如与.Substring(1, s.Length - 2)，或.Trim('"')），然后用","分割字符串：

使用

var elements = line.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None)) 

见C# demo：

var s = "\"123\",\"456\",\"789\""; 
Console.WriteLine(String.Join("|", s.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None))); 
s = "\"123\"\",\"456\",\"789\""; 
Console.WriteLine(String.Join("|", s.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None))); 
s = "\"123\"2\",\"456\",\"789\""; 
Console.WriteLine(String.Join("|", s.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None))); 
s = "\"123\",2\",\"456\",\"789\""; 
Console.WriteLine(String.Join("|", s.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None))); 
s = "\"123\",\"2\",\"456\",\"789\""; 
Console.WriteLine(String.Join("|", s.Substring(1, s.Length - 2).Split(new[] {"\",\""}, StringSplitOptions.None))); 

输出：

123|456|789 
123"|456|789 
123"2|456|789 
123",2|456|789 
123|2|456|789 

Answer 2

你可以尝试这样的正则表达式：

(?<=^"|,").*?(?=","|"$)

解释：

(?<=^"|,") # positive lookbehind: one quote with comma before or at the start .*? # match everything returning at first match (?=","|"$) # positive lookahead: one quote with comma and quote after or at the end

Regex live here.

希望它有帮助。