Formatting text that has been read from text file?

Question

Hi I have a listbox which displays text files when the user clicks a button the user then selects (highlights) a file in the list box and clicks another button to display the conents of the text file in a textbox. How can I format the way in which the text is displayed in the textbox? For example how do I insert a header or separate strings in the text file output? If you know how to do this please help!

Alan · Answer

If Drew is saying that he's not sure what the file contains - only that it contains lines of numbers which are comma separated - then it's possible for code to react to this to some extent. For example the following code will read the numbers no matter how many there are on each line or whether this number is constant for a given file add suitable headers and then right justify the numbers relative to the headers: string line = null; List lines = new List (); StreamReader sr = new StreamReader(abc.txt); while((line = sr.ReadLine()) != null) { lines.Add(line.TrimEnd()); } sr.Close(); string text = ; int max = 0; for (int i = 0 ; i { string[] items = lines[i].Split(new char[]{''} StringSplitOptions.RemoveEmptyEntries); if (items.Length > max) max = items.Length; line = ; for (int j = 0; j { line += String.Format({04} items[j]); if (j } text += line; if (i } string header = ; for (int i = 0; i { header += Col + (i + 1).ToString(); if (i } text = header + Environment.NewLine + Environment.NewLine + text; textBox1.Text = text; I tested this code on this simple abc.txt file: 1234 5678 21235 100724134 Notice that the third line only has three numbers but the others have four. Incidentally for large files you should really be looking at a ListView rather than a TextBox to display them.

Brandon Lewis · Answer

Not quite sure what your after my friend... Im kind of confused. What do you mean you want to split it by number? Do you want to use a specific number as a string delimeter or a line number? Maybe you could show us what the text looks like before formatting and then show us what you want it to look like after its formatted :) You can always use .Split() on a string to split the string and load the split parts into an array but you have to specify a delimeter to tell .Split() where to divide the string. This is most commonly either a comma  or a tab space. Brandon

Drew Taylor · Answer

Thankyou that is very useful I can now add headers which makes it easier to identify what the information is. However for large text files containing numbers I'm still not sure how to split them I'm not sure how it would fit into the code I have. From your example I could prob split the items if the text string contents was specified in the program but my program gets text files from a specified location. Any Suggestions?

Alan · Answer

To add a header just concatenate the header text + a new line character + (possibly) a blank line with the rest of your text. For example: string text = whatever; string header = header; text = header + Environment.NewLine + Environment.NewLine + text; As an alternative to using Environment.NewLine you can use the string 
 on Windows platforms. Otherwise you need to use the various members of the string class to manipulate the text. If for example the text in the file consists of strings separated by commas you can split out the individual strings into an array using the Split() method: string text = HomeMy AccountJob BoardConsulting; string[] items = text.Split(new char[]{''} StringSplitOptions.RemoveEmptyEntries); You can now change the content order or separator of the individual items before recombining them into the text you want to display: text = items[0] + : + items[2].Substring(4) + : + items[3] + : + items[1]; Another thing you could do is to replace the colons in the above line with newline strings so that each item will display on a separate line: text = text.Replace(: Environment.NewLine); textBox1.Text = text; Of course the TextBox's Multiline property needs to be set to true for all this to work. Although this post has only scratched the surface I hope it will have given you a flavour of what you can do to manipulate strings in C#. More powerful manipulations can be done using regular expressions but that's a huge topic on its own :)