What's the quickest method to display large text files in c#?

Question

I'm writing a c# utility that needs to filter and display large text files (over 100MB in size).

The utility opens the text file in read-only mode, should allow scrolling through the text, jumping to a specific line number, searching for text patterns and displaying only specific lines according to user defined filters.

I would like my utility to provide the user with access to the file very soon after pushing the "Load" button and this is where I ran into issues:

I was able to overcome the matter of quickly reading the text file into a DataTable, however, when I wanted to display it in my DataGridView, it took just too long to load. I'm using a DataGridView as I will need to display additional columns near each line of the text.

The only suggestion I could find on the net was to display only a portion of the file each time. This solution sounds perfect for my needs, but raises a few issues:

Shortly after loading the file, the user will want to start performing actions such as: moving to a specific line, searching for text or filtering, hence, loading the file asynchronously into the DataGridView is probably not the best solution to my issue.
Other solutions suggested loading the first N lines of file and the last M lines of the file and adding the missing lines as the user scrolls. Here I had issues with mapping the line numbers in the DataGridView to the line numbers in the DataTable: if I scroll to the end and then start scrolling up, or just jump to a specific line number, how do I know which lines have already been loaded and which haven't?

Has anyone ever tackled such an issue before?

`Has anyone ever tackled such an issue before?` Remember old days where super computers have **64K** RAM — Eser, May 01 '18 at 20:10

score 0 · Accepted Answer · answered May 01 '18 at 19:58

0

DataTable is bulky and slow.

Use WPF and GridView.

Create a class then a List of the class and bind to that.

If you want to dynamically update the UI then ObservableCollection and retrieve data on another thread.

answered May 01 '18 at 19:58

paparazzo

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Also investigate [UI virtualization](https://stackoverflow.com/questions/14456075/). – Dour High Arch May 01 '18 at 21:31
@DourHighArch You get virtualization automatic with GridView (and many of the list controls). – paparazzo May 02 '18 at 11:51
thanks everyone, I'll look into these – meirgold May 02 '18 at 18:39

What's the quickest method to display large text files in c#?

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