String.Remove doesn't work [duplicate]

Question

I have such code and can't understand where is the mistake, despite the fact, that this code pretty easy. So q is a full path, and I need to get required path to Gen_ParamFile

string q = @"C:\ProgramData\RadiolocationQ\script-Data=12^6-12^33.xml";
string _directoryName1 = @"C:\ProgramData\RadiolocationQ";
int Length = _directoryName1.Length + "ascript".Length; 

 string Gen_ParamFile = q;
 Gen_ParamFile.Remove(0, Length); // this line don't  do anything

var Gen_Parfile = Path.Combine(_directoryName1, "GeneralParam-Data" + Gen_ParamFile);

I used function like said here http://msdn.microsoft.com/ru-ru/library/9ad138yc(v=vs.110).aspx

Answer 1

It does, it just doesn't affect the actual string, it creates a new one as a result. Use:

Gen_ParamFile = Gen_ParamFile.Remove(0, Length);

Answer 2

Because String.Remove method returns a new string. It doesn't change original one.

Returns a new string in which a specified number of characters in the current instance beginning at a specified position have been deleted.

Remember, strings are immutable types. You can't change them. Even if you think you change them, you actually create new strings object.

You can assign itself like;

Gen_ParamFile = Gen_ParamFile.Remove(0, Length);

As an alternative, you can use String.SubString method like;

Gen_ParamFile = Gen_ParamFile.SubString(Length);