I have been asked to correct an issue (not related to this question) in a legacy Delphi program. After fixing some issues with missing components, I am now stuck with some GDI Plus functionality, which stops me from compiling the program. One of the functions where this is used is:
function TDownLoadItem.LoadRawBitmapFromStream(var bm: TBitmap): Boolean;
var
image: TGPBitmap;
begin
Result := False;
if Content.Size = 0 then
exit;
// NOTE: Content is a TMemoryStream, declared globally.
image := GDIPlusHelper.LoadBitmapFromStream(Content); // <== This is where the problem is....
try
bm.Width := image.GetWidth;
bm.Height := image.GetHeight;
with TGPGraphics.Create(bm.Canvas.Handle) do
try
DrawImage(image, 0, 0, image.GetWidth, image.GetHeight);
Result := True;
finally
Free;
end;
finally
image.Free;
end;
end;
I think (not sure) the last Delphi version used was 2006, I am on Delphi Rio 10.3.
Online I have managed to find GDI+ 1.2, but this does not solve the problem. The procedure LoadBitmapFromStream does not exit in these libraries. GDIPlusHelper was apparently renamed to GDIPlusHelpers and most code has changed from classes to interfaces. I suspect an older edition of the GDI Plus libraries were used, but I cannot find these.
Reworking the code would be too complex as it would require Content to be an IStream instead of a TMemoryStream. Also, simply using a TBitmap is not feasible either as other code (not shown) uses functionality specific to TGPBitmap (e.g. RotateFlip).
Any suggestions on how to fix/work around this? Thanks in advance!
Related
Our programming dept just spent about a non-mythical man-month tracking down what we think is a bug in a 3rd party component, here's their copyrighted source code:
function TGDIPPicture.GetImageSizes: boolean;
var
multi: TGPImage;
pstm: IStream;
hGlobal: THandle;
pcbWrite: Longint;
begin
result := false;
if Empty then
Exit;
if FDataStream.Size = 0 then
Exit;
hGlobal := GlobalAlloc(GMEM_MOVEABLE, FDataStream.Size);
if (hGlobal = 0) then
raise Exception.Create('Could not allocate memory for image');
try
pstm := nil;
// Create IStream* from global memory
CreateStreamOnHGlobal(hGlobal, TRUE, pstm);
pstm.Write(FDataStream.Memory, FDataStream.Size,#pcbWrite);
multi := TGPImage.Create(pstm);
FWidth := multi.GetWidth;
FHeight := multi.GetHeight;
Result := true;
multi.Free;
finally
GlobalFree(hGlobal);
end;
end;
We found the problem was with TMS's AdvOfficeTabSet. If we added tabs, then it crashed, if we didn't add tabs then it didn't crash. (the crash was one of those un-debuggable app hangs that hits you 10 steps after the real problem).
Following Raymond Chen's advice I replaced GMEM_MOVEABLE with GPTR and it appears to have fixed the problem.
I'm wondering if anyone can tell me if the above code had any legitimate reason for using GMEM_MOVEABLE. AFAIK it's only for the clipboard and it should always be used with GlobalAlloc.
while I was typing this another programmer got an error in the GlobalFree function using my code. So, apparently this doesn't work either. Could really use some help here!
*CreateStreamOnHGlobal is a Windows API function. (which apparently prefers GMEM_MOVEABLE)
*TGPImage is part of TMS's implementation of the GDI+ library.
Jonathan has identified the obvious problem, that being the double free of the HGLOBAL. But as you have found, the use is GMEM_MOVEABLE is correct.
Frankly, the code seems needlessly complex. I suggest you use the built in stream adapter and avoid any GlobalAlloc. To get an IStream you just need to do this:
pstm := TStreamAdapter.Create(FDataStream);
That's it.
I am migrating the code from Delphi 7 to XE2 one of the Graphical module.
we are using TRect variable , the old code is working in Delphi 7 without issue
Ex:
Var
Beold : TRect
begin
Beold.left := Beold.right;
end.
while porting the code to new XE2 we are facing the issue
E0264 : Left side cannot be assigned to
Can you please explain what is the changes in XE2 TRect and D7, how we can assign the valuse
The code you posted compiles and runs fine in a quick Delphi test app, so it's not your real code.
I'd suspect what you've hit is a change in the with statement when it's related to using properties, however. There was a bug in previous versions of Delphi that existed for many years that was finally fixed recently. IIRC, it was first mentioned in a note in the README.HTML file for D2010. It's been added to the documentation in XE2 (not as a behavior change, but the new behavior is documented). The documentation is located here at the docwiki.
(Additional info: It must have been 2010 where it changed; Marco Cantù's Delphi 2010 Handbook mentions it on page 111 as "The With Statement Now Preserves Read-Only Properties" which describes this behavior and the solution I indicated below.)
Instead of accessing the property of a class directly using a with statement, you now need to declare a local variable, and read and write the whole thing directly (error handling omitted for clarity - yes, I know there should be a try..finally block to free the bitmap).
var
R: TRect;
Bmp: TBitmap;
begin
Bmp := TBitmap.Create;
Bmp.Width := 100;
Bmp.Height := 100;
R := Bmp.Canvas.ClipRect;
{ This block will not compile, with the `Left side cannot be assigned to` error
with Bmp.Canvas.ClipRect do
begin
Left := 100;
Right := 100;
end;
}
// The next block compiles fine, because of the local variable being used instead
R := Bmp.Canvas.ClipRect;
with R do
begin
Left := 100;
Right := 100;
end;
Bmp.Canvas.ClipRect := R;
// Do other stuff with bitmap, and free it when you're done.
end.
turns out, using
with (Bmp.Canvas.ClipRect) do
begin
Bottom := 100;
end;
throws error: [Left side cannot be assigned to]
Yet,
with Bmp.Canvas.ClipRect do
begin
Bottom := 100;
end;
does not.
Delphi 10.3.3 is just as finicky about parenthesis as the older versions.
Delphi 2010 has a nice set of new file access functions in IOUtils.pas (I especially like the UTC versions of the date-related functions). What I miss so far is something like
TFile.GetSize (const Path : String)
What is the Delphi 2010-way to get the size of a file? Do I have to go back and use FindFirst to access TSearchRec.FindData?
Thanks.
I'm not sure if there's a "Delphi 2010" way, but there is a Windows way that doesn't involve FindFirst and all that jazz.
I threw together this Delphi conversion of that routine (and in the process modified it to handle > 4GB size files, should you need that).
uses
WinApi.Windows;
function FileSize(const aFilename: String): Int64;
var
info: TWin32FileAttributeData;
begin
result := -1;
if NOT GetFileAttributesEx(PChar(aFileName), GetFileExInfoStandard, #info) then
EXIT;
result := Int64(info.nFileSizeLow) or Int64(info.nFileSizeHigh shl 32);
end;
You could actually just use GetFileSize() but this requires a file HANDLE, not just a file name, and similar to the GetCompressedFileSize() suggestion, this requires two variables to call. Both GetFileSize() and GetCompressedFileSize() overload their return value, so testing for success and ensuring a valid result is just that little bit more awkward.
GetFileSizeEx() avoids the nitty gritty of handling > 4GB file sizes and detecting valid results, but also requires a file HANDLE, rather than a name, and (as of Delphi 2009 at least, I haven't checked 2010) isn't declared for you in the VCL anywhere, you would have to provide your own import declaration.
Using an Indy unit:
uses IdGlobalProtocols;
function FileSizeByName(const AFilename: TIdFileName): Int64;
You can also use DSiFileSize from DSiWin32. Works in "all" Delphis. Internally it calls CreateFile and GetFileSize.
function DSiFileSize(const fileName: string): int64;
var
fHandle: DWORD;
begin
fHandle := CreateFile(PChar(fileName), 0, 0, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if fHandle = INVALID_HANDLE_VALUE then
Result := -1
else try
Int64Rec(Result).Lo := GetFileSize(fHandle, #Int64Rec(Result).Hi);
finally CloseHandle(fHandle); end;
end; { DSiFileSize }
I'd like to mention few Pure Delphi ways. Though i think Deltics made a most speed-effective answer for Windows platform, yet sometimes you want just rely on RTL and also make portable code that would work in Delphi for MacOS or in FreePascal/Virtual Pascal/whatever.
There is FileSize function left from Turbo Pascal days.
http://turbopascal.org/system-functions-filepos-and-filesize
http://docwiki.embarcadero.com/CodeExamples/XE2/en/SystemFileSize_(Delphi)
http://docwiki.embarcadero.com/Libraries/XE2/en/System.FileSize
The sample above lacks "read-only" mode setting. You would require that to open r/o file such as one on CD-ROM media or in folder with ACLs set to r/o. Before calling ReSet there should be zero assigned to FileMode global var.
http://docwiki.embarcadero.com/Libraries/XE2/en/System.FileMode
It would not work on files above 2GB size (maybe with negative to cardinal cast - up to 4GB) but is "out of the box" one.
There is one more approach, that you may be familiar if you ever did ASM programming for MS-DOS. You Seek file pointer to 1st byte, then to last byte, and check the difference.
I can't say exactly which Delphi version introduced those, but i think it was already in some ancient version like D5 or D7, though that is just common sense and i cannot check it.
That would take you an extra THandle variable and try-finally block to always close the handle after size was obtained.
Sample of getting length and such
http://docwiki.embarcadero.com/Libraries/XE2/en/System.SysUtils.FileOpen
http://docwiki.embarcadero.com/Libraries/XE2/en/System.SysUtils.FileSeek
Aside from 1st approach this is int64-capable.
It is also compatible with FreePascal, though with some limitations
http://www.freepascal.org/docs-html/rtl/sysutils/fileopen.html
You can also create and use TFileStream-typed object - which was the primary, officially blessed avenue for file operations since Delphi 1.0
http://www.freepascal.org/docs-html/rtl/classes/tfilestream.create.html
http://www.freepascal.org/docs-html/rtl/classes/tstream.size.html
http://docwiki.embarcadero.com/Libraries/XE2/en/System.Classes.TFileStream.Create
http://docwiki.embarcadero.com/Libraries/XE2/en/System.Classes.TStream.Size
As a side note, this avenue is of course integrated with aforementioned IOUtils unit.
http://docwiki.embarcadero.com/Libraries/XE3/en/System.IOUtils.TFile.OpenRead
This is a short solution using FileSize that does the job:
function GetFileSize(p_sFilePath : string) : Int64;
var
oFile : file of Byte;
begin
Result := -1;
AssignFile(oFile, p_sFilePath);
try
Reset(oFile);
Result := FileSize(oFile);
finally
CloseFile(oFile);
end;
end;
From what I know, FileSize is available only from XE2.
uses
System.Classes, System.IOUtils;
function GetFileSize(const FileName : string) : Int64;
var
Reader: TFileStream;
begin
Reader := TFile.OpenRead(FileName);
try
result := Reader.Size;
finally
Reader.Free;
end;
end;
I am upgrading a app to Delphi 2009. The app uses Soap and we compress the soap request and response streams using Zlib. This works fine in Delphi 2006 but not in Delphi 2009.
So I went back to Delphi 2006 and changed to use FastZlib. It all worked fine in Delphi2006 but does not work in Delphi 2009 and I get Decompress errors.
Has anyone else had this problem?
How do I go about fixing this?
Sandeep
I just looked through the built-in Zlib.pas and it appears to have been updated for D2009 properly. What's giving you problems?
In delphi 2006 I had following methods to compress and decompress using Zlib(from Delphi 2006)
procedure CompressStream(inpStream, outStream: TStream);
var
InpBuf, OutBuf: Pointer;
InpBytes, OutBytes: Integer;
begin
InpBuf := nil;
OutBuf := nil;
try
GetMem(InpBuf, inpStream.Size);
inpStream.Position := 0;
InpBytes := inpStream.Read(InpBuf^, inpStream.Size);
CompressBuf(InpBuf, InpBytes, OutBuf, OutBytes);
outStream.Write(OutBuf^, OutBytes);
finally
if InpBuf <> nil then FreeMem(InpBuf);
if OutBuf <> nil then FreeMem(OutBuf);
end;
end;
{ Decompress a stream }
procedure DecompressStream(inpStream, outStream: TStream);
var
InpBuf, OutBuf: Pointer;
OutBytes, sz: Integer;
begin
InpBuf := nil;
OutBuf := nil;
sz := inpStream.Size - inpStream.Position;
if sz > 0 then
try
GetMem(InpBuf, sz);
inpStream.Read(InpBuf^, sz);
DecompressBuf(InpBuf, sz, 0, OutBuf, OutBytes);
outStream.Write(OutBuf^, OutBytes);
finally
if InpBuf <> nil then FreeMem(InpBuf);
if OutBuf <> nil then FreeMem(OutBuf);
end;
outStream.Position := 0;
end;
What should I change for these to work in Delphi 2009?
Something that might be worth trying - compress your data, and then UUENCODE it, and on the other end, reverse the process. This will detect if some code is not dealing with embedded zero's properly.
Sorry, this is only a partial solution to help you narrow the problem down.
The original poster's was clear about the problem: CompressBuf and DecompressBuf are GONE.
I also have a project that compiles just fine in D7, but fails to compile in D2010 because it can't find "CompressBuf" or "DecompressBuf".
A search using D7's very pleasant find command locates the routines at
c:\Program Files\Borland\Delphi7\Source\Rtl\Common\ZLib.pas
But searching with D2010's (awkward separate) "Find in Files" command fails to locate CompressBuf or DecompressBuf anywhere.
It's very disturbing that upgrading the IDE causes routines used and needed in projects to disappear!
in D2009 you can use ZCompress/ZDecompress instead of CompressBuf/DecompressBuf
I test it and there is no problem.
Using the DelphiTwain files from http://delphitwain.sourceforge.net/ and am getting some weird behavior.
After each scan a little more memory is being held onto.
After an hour or so of repetitive scans, the image scanned is zoomed in approxamately 10 times, and just the upper-left square inch is stored.
Has anyone had similar issues, or have some suggestions?
Code below...
try
try
Twain := TDelphiTwain.Create(self);
Twain.OnTwainAcquire := TwainAcquireHandler; //manually set the event handler
Twain.OnSourceFileTransfer := TwainSourceFileTransfer;
Twain.OnSourceSetupFileXfer := TwainSourceSetupFileXfer;
Twain.LoadLibrary;
Twain.LoadSourceManager;
Twain.Source[0].Loaded := TRUE;
Twain.Source[0].TransferMode := ttmFile;
Twain.Source[0].EnableSource(false, false);
except on e : exception do
showmessage('Error loading Scanner.');
end;
try
while Twain.Source[0].Enabled do
Application.ProcessMessages;
except on e : exception do
showmessage('Error Scanning Packing List.');
end;
finally
Twain.Source[0].Loaded := FALSE;
Twain.UnloadSourceManager(true);
Twain.UnloadLibrary;
Twain.Destroy;
end;
Since the TDelphiTwain appears to be a component you are creating in code, I would recommend passing in nil for the constructor and calling the .Free method or (as suggested by Joseph) FreeAndNil.
Twain := TDelphiTwain.Create(nil);
try
try
Twain.OnTwainAcquire := TwainAcquireHandler; //manually set the event handler
Twain.OnSourceFileTransfer := TwainSourceFileTransfer;
Twain.OnSourceSetupFileXfer := TwainSourceSetupFileXfer;
Twain.LoadLibrary();
Twain.LoadSourceManager();
Twain.Source[0].Loaded := True;
Twain.Source[0].TransferMode := ttmFile;
Twain.Source[0].EnableSource(False, False);
except on e : exception do
showmessage('Error loading Scanner.');
end;
try
while Twain.Source[0].Enabled do
Application.ProcessMessages;
except on e : exception do
showmessage('Error Scanning Packing List.');
end;
Twain.Source[0].Loaded := False;
Twain.UnloadSourceManager(True);
Twain.UnloadLibrary();
finally
FreeAndNil(Twain);
end;
I would also recommend better exception handling, but not related to question you asked. The only thing users will see and report to you (or worse, the quiet guy in the corner responsible for your IT support who loves to get non-descriptive errors from users) is 'Error doing something'
Good luck
Another area to look at is if the scanner supports WIA (Windows Image Acquisition)
var
DevMgr: IDeviceManager;
Scanner: Idevice;
Picture: IItem;
Image: OleVariant;
AImage: IImageFile;
begin
DevMgr := CreateOleObject('WIA.DeviceManager') as IDeviceManager;
// Figure out which device is the scanner
Scanner:= DevMgr.DeviceInfos.Item[1].Connect;
//Command: Figure out which command scans..
Picture := Scanner.ExecuteCommand(Scanner.Commands.Item[1].CommandID);
//Transfer as JPG
Image := Picture.Transfer(Picture.Formats.Item[1]);
//Save the image
AImage := IImageFile(Image);
AImage.SaveFile('c:\wia_viaScanner\image.' + AImage.FileExtension);
end;
More info on the WIA library can be found here..
http://msdn.microsoft.com/en-us/library/ms629859(VS.85).aspx
Examining the code within these calls may be fruitful:
TwainAcquireHandler;
TwainSourceFileTransfer;
TwainSourceSetupFileXfer;
Do any of those create any objects without freeing them?
If you are using Delphi 2006 or higher, then you can add this line to your .DPR file:
ReportMemoryLeaksOnShutdown := True;
Then reproduce the memory leak, close your app... and it will describe the leaks in detail. A little more info about this can be found here.
On another note, I'd suggest replacing
Twain.Destroy;
with
FreeAndNil(Twain);
.Destroy will call the destructor directly, while FreeAndNil is a safer alternative that will also prevent the "Twain" variable from pointing anywhere dangerous. (See the accepted answer to this question).
I can't address the problem you're reporting but you have a busy loop there that will gobble CPU time.
What are you doing when you get the Image, did you keep in memory?
Or the library can have some memory leaks, you can check if it is true with FastMM4.
to KevinRF:
I need to use WIA automation in Delphi 7 project. I registered WIAAut.dll in my system, import this library into Delphi and past your programm code into my project and got some errors:
Scanner:= DevMgr.DeviceInfos.Item[1].Connect;
Types of actual and formal var parameters must be identical
in "Item" must be Item[var Index: OleVariant], but "1" is integer
What's wrong, what i need to made it works?