Win Forms - Open as a File or Stream

[OldPCGuy]

So with the OpenFileDialog component I can open the file as a File, or a Stream.

For reading and parsing text files which is generally preferred?

[Thomas1965]

Actually the OpenFileDialog gives you only the filename(s). To open a file you can use the System::IO::File class.
https://msdn.microsoft.com/en-us/library/system.io.file(v=vs.110).aspx?cs-save-lang=1&cs-lang=cpp#code-snippet-1
How to process the file depends on the format of the file.