Delete files in Delphi

http://wiki.freepascal.org/mysql


I checked the readonly property of the files. The directory d:\multifilter was write-protected (I could not change this) but all files in it could be manipulated ad libitum.
So I checked if with inclusion of

Code: Pascal  [Select]

1. deletefile(d:\multifilter\b0.jpg);

at the beginning of the program b0.jpg was deleted, ok.

Also

Code: Pascal  [Select]

1. files:='d:\multifilter\');
2. deletefile(files+'b1.jpg');

worked.

Also

Code: Pascal  [Select]

1.   files:='d:\multifilter\');
2.   n:=2;
3.   Str(n,nstring);
4.   fbstring:=files+'b'+nstring+'.jpg';
5.   deletefile(fbstring);

worked!

Also

Code: Pascal  [Select]

1.   for n:=0 to nmax-1 do
2.   begin
3.   Str(n,nstring);
4.   fbstring:=files+'b'+nstring+'.jpg';
5.   deletefile(fbstring);
6.   end;

worked!!!

But the deletefile() directly before the savefile() (as discussed before) later on in the program does not work. Very rare! (The savefile() alone did not overwrite the old files - this was the cause of the whole problem).
So, I put the deletes at the first possible place (when it is clear if and how many files have to be deleted). And it works!




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Example code : Try to delete a file twice

var   fileName : string;   myFile   : TextFile;   data     : string; begin   // Try to open a text file for writing to   fileName := 'Test.txt';   AssignFile(myFile, fileName);   ReWrite(myFile);   // Write to the file   Write(myFile, 'Hello World');   // Close the file   CloseFile(myFile);   // Reopen the file in read mode   Reset(myFile);   // Display the file contents   while not Eof(myFile) do   begin     ReadLn(myFile, data);     ShowMessage(data);   end;   // Close the file for the last time   CloseFile(myFile);   // Now delete the file   if deletefile(fileName)   then ShowMessage(fileName+' deleted OK')   else ShowMessage(fileName+' not deleted');   // Try to delete the file again   if deletefile(fileName)   then ShowMessage(fileName+' deleted OK again!')   else ShowMessage(fileName+' not deleted, error = '+                    IntToStr(GetLastError)); end;

Show full unit code

Hello World    Test.txt deleted OK    Test.txt not deleted, error = 2