There is no quick and easy CopyFile routine shipped with Delphi. So you have
to cross the i's and dot the t's yourself. This ways is as good as any although
a STREAM might also be used instead of a buffer (by using two TFileStream streams,
and 'create'ing the first by associating it with source file, then 'copying' this
stream to a second stream, which is then 'CopyToFile'd)...
Note that the srcFName and destFName parameters should be FILENAMES INCLUDING FULL
PATH NAMES. -These will have been acquired elsewhere, obviously. Note that src file
is opened using ReSet and dest file is opened using ReWrite, and if dest file
already exists it will be overwritten...
function TInstallForm.CopyFileUsingBuffer(srcFName, destFName: String): Boolean;
type
{define a buffer as a character array type of length maxBufferSize...}
TMyBufferArray = array[1..maxBufferSize] of char;
{and define a pointer type to point into the buffer...}
TMyBuffer = ^TMyBufferArray;
var
buffer: TMyBuffer;
srcFile, destFile: File;
bytesRead, bytesWritten, i: LongInt;
readOrWriteError: Boolean;
begin
bytesRead := 0;
try {to allocate memory for the buffer...}
getmem(buffer, maxBufferSize);
AssignFile(srcFile, srcFName);
AssignFile(destFile, destFName);
try {to open both source and destination files...}
reSet(srcFile, 1);
reWrite(destFile, 1);
try
repeat
{put source file data into into the buffer
and write buffer to destination file...}
blockRead(srcFile, buffer^, sizeof(buffer^), bytesRead);
blockWrite(destFile, buffer^, bytesRead, bytesWritten);
until ((bytesRead < maxBufferSize) or (bytesRead = 0)
or (bytesWritten <> bytesRead));
finally
closefile(srcFile);
closeFile(destFile);
end; {putting source file data into memory}
except on E: EInOutError do
begin
{you COULD call some kind of GetError routine here
to retrieve the exact error code if you wanted to...}
readOrWriteError := True;
end
end; {trying to open source file}
finally
freemem(buffer, maxBufferSize);
end;
if (readOrWriteError = True) then Result := True;
if (readOrWriteError = False) then Result := False;
end;