[SOLVED] Bizarre File Access Problem with TFileStream

[Gizmo]

Sorry to resort to asking this, as the answer must surely be an obvious one I am missing.

I am using TFileListBox with Lazarus 2.0.10 (also tried with 2.0.4) to show files in a folder to the user.

When the user clicks a file, I want to load the content of it into TMemoryStream and show it in Memo1. Super simple.

Yet for some reason, the program says it is unable to open the file.

Code: [Select]

Unable to open file "C:\temp\test.html": The system cannot find the file specified.

Press OK to ignore and risk data corruption.
Press Abort to kill the program.


Code: Pascal  [Select][+][-]

1. procedure TForm1.FileListBox1Click(Sender: TObject);
2. var
3.   EncodedStream : TFileStream;
4.   SelectedFile : string;
5. begin
6.   SelectedFile := ExpandFileName(Filelistbox1.Items[FileListBox1.ItemIndex]); // THIS WAY CAUSES THE ERROR TO BE RAISED BELOW
7.   // SelectedFile := 'C:\temp\test.html'; // YET IF I HARD CODE THE EXACT SAME PATH, AN ERROR IS NOT RAISED BELOW
8.   try
9.   EncodedStream := TFileStream.Create(SelectedFile, fmOpenRead or fmShareDenyNone);  //*** ERROR IS RAISED HERE ***
10.   EncodedStream.Position := 0;
11.   Memo1.Lines.LoadFromStream(EncodedStream);    
12. ...
13.  

What on Earth am I missing? I've used ShowMessage(SelectedFile) and it returns exactly the right path and name. Are any of you able to download the attached sample project and get it to display a selected non-binary file in Memo1?

[lucamar]

Does it work if you use TrimAndExpandFilename() (in package LazUtils, unit LazFileUtils) instead of ExpandFilename()?

It shoudn't matter but it's worth testing it, in case there is any strange, non-visible character in the name as returned by the filelistbox

[Gizmo]

Thanks for the input, but no sir. I get a project exception now but on same line still.

Are you able to try the project attached? I can't work out if it is just my computer or not.

[Sieben]

When I run that project, ExpandFileName results in a filename composed of the current directory and the filename in the listbox. Did you try sth like

Code: Pascal  [Select][+][-]

1. SelectedFile := AppendpathDelim(FileListBox1.Directory)+(Filelistbox1.Items[FileListBox1.ItemIndex]);

[Gizmo]

Well how odd.

Yes, thank you, that has worked. But, I have no understanding why because the debugger reported correct path and name

[Sieben]

I don't have a clue. But I would expect it to work like that since ExpandFileName has no knowledge of the FileListBox and it's settings.

[Sieben]

Just to bring this to a proper end - TFileListBox has a public property named FileName, so:

Code: Pascal  [Select][+][-]

1. SelectedFile := FileListBox1.FileName;