TFileStream with TStreamReader question

[hsauro 39]

What is the advantage of using TFileStream with TStreamReader compared passing the filename directly to TStreamReader?

 

For example, what is the difference between these two:

 

    f = TStreamReader.Create (fileName)

 

or

 

    f = TStreamReader.Create (TFileStream.Create (fileName, fmOpenRead))

[Dave Nottage 553]

TStreamReader.Create (fileName) passes the flags as:

 

fmOpenRead or fmShareDenyWrite

 

Sadly, none of the overloads allow you to change this. Worse still: its counterpart TStreamWriter.Create can fail on platforms other than iOS because the flags don't include fmShareDenyWrite

Edited November 19, 2018 by Dave Nottage

[hsauro 39]

Thanks for that. So it's better to use f = TStreamReader.Create (TFileStream.Create (fileName, fmOpenRead)) because one has more control over the flags.