c# - Process each line separately in selected text -

i'm trying select set of lines , process each line separately in text document using c# language. how can separate lines process? tried these codes , got struck. can please me this?

envdte.dte dte = mypackage.mypackagepackage.getglobalservice(typeof(envdte.dte)) envdte.dte; envdte.textselection text = (dte.activedocument.selection envdte.textselection); 

if reading text file code you:

string filetoread = "d:\\temp.txt";    // temp.txt file read  if (file.exists(filetoread)) {     streamreader reader = new streamreader(filetoread);         {          textbox1.text += reader.readline() + "\r\n";    // read each line , pass textbox1      } while (reader.peek() != -1);     reader.close(); // close file  }