如何提取字符串的某些部分？

Question

I have a string = "C:\\Users\\Desktop\\bin\\data\\so on"

I want to extract just the "C:\\Users\\Desktop\\" part.. what is the easiest way to get the result ?

Answer 1

string s = @"C:\Users\Desktop\bin\data\so on";
string result = String.Join("\\",s.Split('\\').Take(3));

Result C:\\Users\\Desktop

Answer 2

Take in to account that there're two possible directory separators (your input looks like a path):

  String s = "C:\Users\Desktop\bin\data\so on";

  String result = String.Join(Path.DirectorySeparatorChar.ToString(), 
                              s.Split(Path.DirectorySeparatorChar, 
                                      Path.AltDirectorySeparatorChar).Take(3));

Or if you want to keep on until "/bin" or "\\bin" is found you should change Take to TakeWhile :

  String result = String.Join(Path.DirectorySeparatorChar.ToString(), 
                          s.Split(Path.DirectorySeparatorChar, 
                                  Path.AltDirectorySeparatorChar).TakeWhile(
                                    x => !String.Equals(x, "bin", StringComparison.OrdinalIgnoreCase)));

Naive soultion as Substring(@"\\bin") can be dangerous on inputs like that "C:\\Windows\\MyBins\\Bin\\SomeStaff"