I tried the indexof and substring and now im getting error again:

[Chocolade]

If im using this code just on a text file i created that containing one long string like "dann123ylip123sharon123daniel" so its working im ggeting first time result : "dann" then "dannylip" then "dannylipsharon"

But now in the code here im using an xml file wich is very big and im using three indexof to get the specific text i want from the the file. Not like im using in the test.txt file.

And when im running the program im getting error on line:

Substring1 = ff.Substring(prevIndex, index - prevIndex);
Telling me that Length cannot be less than zero.
Parameter name: length
And when im putting the mouse on it i see that : index = 368 and prevIndex = 1194945

So what wrong with this code ( formula ) ? I thought it will work on any text file or this xml file.
Cuz when im looking on G the string G in this code its containing the text i wanted from the xml file.

This is the code:

private void assetid_search()
        {
            string Substring1;
            string Substring2;
            var index = 0;
            var prevIndex = 0;
            var test = string.Empty;
            w=new StreamWriter(@"d:\german.txt");
            while (true)
            {
                index = tt.IndexOf("Text value", index + 1);
                if (index == -1)
                {
                    break;
                }
                int t = tt.IndexOf("\"", index);
                int y = tt.IndexOf(">",t);
                g = tt.Substring(t,y-t);
                listBox2.Items.Add(g);
                Substring1 = ff.Substring(prevIndex, index - prevIndex);
                string remainingString = ff.Substring(index + g.Length);
                int remainingStringLenght = remainingString.Contains(g) ? remainingString.IndexOf(g) : remainingString.Length;
                Substring2 = ff.Substring(index + g.Length, remainingStringLenght);
                test += Substring1 + Substring2;
                prevIndex = index + g.Length + remainingStringLenght;
                w.WriteLine(test);
            }
            w.Close();
        }
 

Thanks.