使用正則表達式替換模式替換字符串

Question

基本上我正在處理CSV文件並在C＃中逐行讀取它。我有一個字符串輸入（一行），並試圖找到一個正則表達式模式，並使用另一個正則表達式模式替換它，但結果不是我所期望的。

var input = "\"efgh ,ijkl123,\",abcd , \"efgh ,ijkl123,\",mnop456 \"efgh ,ijkl123,\""; 

在輸出我需要用分號其中那些雙引號是逗號彼此之間更換雙引號之間的內部逗號。

雙引號和外部逗號（雙引號外的逗號之間）它可以只有空格。

因此，我希望輸出爲："efgh ;ijkl123,",abcd , "efgh ;ijkl123,",mnop456 "efgh ,ijkl123,"

我的代碼：

var pattern = @".*,\s*""(.*,+.*)+""\s*,.*"; 
var replacePattern = @".*,\s*""(.*;+.*)+""\s*,.*"; 
if (Regex.IsMatch(input, pattern)) 
{ 
    var output = Regex.Replace(input, pattern, replacePattern); 
} 

但在運行我的代碼，輸出爲：。 ，\ s「（。; +。）+」\ s *，。*這是replacePattern。

EDIT更多輸入採樣，並輸出作爲預期：

1. 輸入abcd , "efgh ,ijkl123,",mnop456

   輸出abcd , "efgh ;ijkl123;",mnop456

2. 輸入"efgh ,ijkl123,",abcd , "efgh ,ijkl123,",mnop456 "efgh ,ijkl123,"

   輸出"efgh ;ijkl123;",abcd , "efgh ;ijkl123;",mnop456 "efgh ,ijkl123,"

3. 輸入,"efgh ,ijkl123,",abcd" , "efgh ijkl123,",mnop456 "efgh ,ijkl123,","efgh ,ijkl123,"mnop456

   輸出,"efgh ;ijkl123;",abcd" , "efgh ijkl123;",mnop456 "efgh ,ijkl123,","efgh ,ijkl123,"mnop456

4. 輸入,"efgh" ,ijkl123,",abcd" , "efgh ijkl123,",mnop456 "efgh ,ijkl123,","efgh ,ijkl123,"mnop456

   輸出,"efgh" ,ijkl123,";abcd" , "efgh ijkl123;",mnop456 "efgh ,ijkl123,","efgh ,ijkl123,"mnop456

5. 輸入efgh ,ijkl123,",abcd , "efgh ,ijkl123,",mnop456 "efgh ,ijkl123,"

   輸出efgh ,ijkl123,",abcd , "efgh ;ijkl123;",mnop456 "efgh ,ijkl123,"

Answer 1

好吧，這有點棘手，我敢肯定有人會建議比我更好的正則表達式。假設你輸入的文字是：

"efgh ,ijkl123,",abcd , "efgh ,ijkl123,",mnop456 "efgh ,ijkl123," 

你可以試試：

var data = "\"efgh ,ijkl123,\",abcd , \"efgh ,ijkl123,\",mnop456 \"efgh ,ijkl123,\""; 

var rx = @"(?<=(^|,[ \t]*))\""[^\""\n]+\""(?=[ \t]*(,|$))"; 

var matches = Regex.Matches (data, rx); 

foreach (Match match in matches) { 
    data = new Regex (match.Value). 
     Replace(data, match.Value.Replace (',', ';'), 1); 
} 

Console.WriteLine (data); 

它會發出：

"efgh ;ijkl123;",abcd , "efgh ;ijkl123;",mnop456, "efgh ,ijkl123," 

以上代碼基本上與;半結腸代替雙引號之間的所有,昏迷。

Answer 2

不知道它是非常有效的，但工程。歡迎提出進一步改進建議。

string input = "\"efgh ,ijkl123,\",abcd , \"efgh ,ijkl123,\",mnop456 \"efgh ,ijkl123,\"";; 

Regex.Matches(input, "\"([^\"]*)\"(,)") // Extract string between quotes followed by ','. 
.Cast<Match>() 
    .ToList() 
    .ForEach(m=> input = input.Replace(m.Value, m.Value.Replace(",",";")) // for each match replace with ';' inserted match. 
           .Replace(";\";",",\",")); // a hack, should have done it better 

輸出繼電器：

"efgh ;ijkl123,",abcd , "efgh ;ijkl123,",mnop456 "efgh ,ijkl123," 

工作Demo