Regex.Split空白

Question

string pattern = @"(if)|(\()|(\))|(\,)"; 
string str = "IF(SUM(IRS5555.IRs001)==IRS5555.IRS001,10,20)"; 
string[] substrings = Regex.Split(str,pattern,RegexOptions.IgnorePatternWhitespace | RegexOptions.IgnoreCase) ; 
foreach (string match in substrings) 
{ 
    Console.WriteLine("Token is:{0}", match); 
} 

进出卖出期权

Token is: 
Token is:IF 
Token is: 
Token is:(
Token is:SUM 
Token is:(
Token is:IRS5555.IRs001 
Token is:) 
Token is:==IRS5555.IRS001 
Token is:, 
Token is:10 
Token is:, 
Token is:20 
Token is:) 
Token is: 

正如你可以在1,3和最后一个记号看空字符串，我不能够理解为什么这种结果，有在给定的字符串中不是空字符串。

我不希望这是结果

Answer 1

尝试：

 string pattern = @"(if)|(\()|(\))|(\,)"; 
     string str = "IF(SUM(IRS5555.IRs001)==IRS5555.IRS001,10,20)"; 
     var substrings = Regex.Split(str, pattern, RegexOptions.IgnoreCase).Where(n => !string.IsNullOrEmpty(n)); 
     foreach (string match in substrings) 
     { 
      Console.WriteLine("Token is:{0}", match); 
     } 

Answer 2

这是因为 “IF” 和 “（” 是分离器和因为没有什么的“IF”左侧，“IF”和“（”之间没有任何空白条目，从模式中删除“IF”。

string pattern = @"(\()|(\))|(\,)"; 

---

UPDATE

您可以搜索的标记，而不是分割字符串

var matches = Regex.Matches(str, @"\w+|[().,]|=="); 

这exacly返回文本的标记。

string[] array = matches.Cast<Match>().Select(m => m.Value).ToArray(); 

 
    [0]: "IF" 
    [1]: "(" 
    [2]: "SUM" 
    [3]: "(" 
    [4]: "IRS5555" 
    [5]: "." 
    [6]: "IRs001" 
    [7]: ")" 
    [8]: "==" 
    [9]: "IRS5555" 
    [10]: "." 
    [11]: "IRS001" 
    [12]: "," 
    [13]: "10" 
    [14]: "," 
    [15]: "20" 
    [16]: ")" 

---

UPDATE

另一个Regex模式可以用Regex.Split一起尝试是

@"\b" 

它将在文字文本分割boundries

 
    [0]: "" 
    [1]: "IF" 
    [2]: "(" 
    [3]: "SUM" 
    [4]: "(" 
    [5]: "IRS5555" 
    [6]: "." 
    [7]: "IRs001" 
    [8]: ")==" 
    [9]: "IRS5555" 
    [10]: "." 
    [11]: "IRS001" 
    [12]: "," 
    [13]: "10" 
    [14]: "," 
    [15]: "20" 
    [16]: ")"