C# - Substring: index and length must refer to a location within the string

Question

I have a string that looks like

string url = \"www.example.com/aaa/bbb.jpg\";

\"www.example.com/\" is 18 fixed in length. I want to get th

Answer 1

Your mistake is the parameters to Substring. The first parameter should be the start index and the second should be the length or offset from the startindex.

string newString = url.Substring(18, 7);

If the length of the substring can vary you need to calculate the length.

Something in the direction of (url.Length - 18) - 4 (or url.Length - 22)

In the end it will look something like this

string newString = url.Substring(18, url.Length - 22);

Answer 2

string newString = url.Substring(18, (url.LastIndexOf(".") - 18))

Answer 3

Here is another suggestion. If you can prepend http:// to your url string you can do this

  string path = "http://www.example.com/aaa/bbb.jpg";
  Uri uri = new Uri(path);            
  string expectedString = 
      uri.PathAndQuery.Remove(uri.PathAndQuery.LastIndexOf("."));

Answer 4

You need to find the position of the first /, and then calculate the portion you want:

string url = "www.example.com/aaa/bbb.jpg";
int Idx = url.IndexOf("/");
string yourValue = url.Substring(Idx + 1, url.Length - Idx - 4);

Answer 5

How about something like this :

string url = "http://www.example.com/aaa/bbb.jpg";
Uri uri = new Uri(url);
string path_Query = uri.PathAndQuery;
string extension =  Path.GetExtension(path_Query);

path_Query = path_Query.Replace(extension, string.Empty);// This will remove extension

Answer 6

Try This:

 int positionOfJPG=url.IndexOf(".jpg");
 string newString = url.Substring(18, url.Length - positionOfJPG);