Since this is your previous question under another name, please give all the information!
You have the code to select a file (in your example above)
You have the code to read data from a file (in my previous answer)
You have the code to sort the data (in my previous answer)
All you don't have is the code to put the sorted data into a multiline Textbox, and frankly, that's not exactly rocket science:
string[] lines = File.ReadAllLines(fileName);
...
myTextBox.Lines = lines;
So what is the problem? Just put all the bits together!