System.Close Function

Terminates the association between a file variable and an external file.

Pascal

procedure Close(var F);

C++

Close( F);

File

System

Description

Close is provided for backward compatibility with existing code. When writing new applications in Delphi, use CloseFile instead.

F is a file variable of any file type opened using Reset, Rewrite, or Append. The external file associated with F is completely updated and then closed, freeing the file handle for reuse.

Delphi Examples:

Copy Code

{
This example reads an entire file into a buffer with one
command and then writes it into a saved file.  Validate
the saved file contents.
}
procedure TForm1.Button1Click(Sender: TObject);
var
  FromF, ToF: file;
  NumRead, NumWritten: Integer;
  Buf: array[1..2048] of Char;
begin
  if OpenDialog1.Execute then     { Display Open dialog box }
  begin
    AssignFile(FromF, OpenDialog1.FileName);
    Reset(FromF, 1);    { Record size = 1 }
    if SaveDialog1.Execute then      { Display Save dialog box}
    begin
      AssignFile(ToF, SaveDialog1.FileName);    { Open output file }
      Rewrite(ToF, 1);  { Record size = 1 }
      Canvas.TextOut(10, 10, 'Copying ' + IntToStr(FileSize(FromF))
        + ' bytes...');
      repeat
        System.BlockRead(FromF, Buf, SizeOf(Buf), NumRead);
        BlockWrite(ToF, Buf, NumRead, NumWritten);
      until (NumRead = 0) or (NumWritten <> NumRead);
      // Use CloseFile rather than Close; Close provided for backward compatibility
      CloseFile(FromF);
      CloseFile(ToF);
      Canvas.TextOut(120, 10, ' done.');
    end;
  end;
end;