retrieve image saved on database [duplicate] - delphi

Question

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How to insert image into database using TADOQuery Component Only
(2 answers)
Store images in MS-Access Database using Delphi6
(1 answer)
Closed 10 years ago.
I'm using this code to load images into my Timage:
begin
if OpenPictureDialog1.Execute(Self.Handle) then
Image1.Picture.LoadFromFile(OpenPictureDialog1.FileName);
end;
Then I'm using this code to store into my ms access database:
var
AStream : TMemoryStream;
begin
Adotable1.Append;
AStream := TMemoryStream.Create;
try
Image1.Picture.Graphic.SaveToStream(AStream);
AStream.Position := 0;
if Adotable1.Active then
begin
TBlobField(Adotable1.FieldByName('Termograma')).LoadFromStream(AStream);
end;
finally
AStream.Free;
end;
adotable1.Post;
But now I want to display these saved images on a Timage, can anyone help me?
The images are .jpeg format

Answer 1

As far as TPicture is not able to decide which kind of TGraphic it has to create for loading, since a stream does not have an extension like a filename you have to decide it, and assign the Graphic.
In this case a TJPEGImage to the Picture.
var
JPG:TJPEGImage;
ms:TMemoryStream;
begin
JPG:=TJPEGImage.Create;
ms:=TMemoryStream.Create;
try
TBlobField(AdoTable1.FieldByName('Termograma')).SaveToStream(ms);
ms.Position := 0;
JPG.LoadFromStream(ms);
Image2.Picture.Assign(JPG);
finally
JPG.Free;
ms.Free;
end;
end;
The following unit is able to store diffent graphicformats in blobfields.
Storage is not compatible to simple storing of image data because information about then graphicformat is stored too, to give the ability to create the needed class for loading.
unit LoadSaveImageBlobs;
// 20120224 by Thomas Wassermann
// Adapt. RegisterClasses and uses for your requirements
// based on an Idea of Emiliano Sos
interface
uses Classes,DB,Graphics,Jpeg,PngImage;
Procedure SavePicture2Blob(Blob: TBlobField; Picture: TPicture);
Procedure LoadPictureFromBlob(Picture: TPicture; Blob: TBlobField);
implementation
Procedure SavePicture2Blob(Blob: TBlobField; Picture: TPicture);
var
ms, ms2: TMemoryStream;
theClassName: AnsiString;
len: Byte;
begin
ms := TMemoryStream.Create;
try
Blob.Clear;
theClassName := Picture.Graphic.ClassName;
len := Length(theClassName);
ms.WriteBuffer(len, 1);
if len > 0 then
ms.WriteBuffer(theClassName[1], len);
ms2 := TMemoryStream.Create;
try
Picture.Graphic.SaveToStream(ms2);
ms2.Position := 0;
if ms2.Size > 0 then
ms.CopyFrom(ms2, ms2.Size);
finally
ms2.Free;
end;
Blob.LoadFromStream(ms);
finally
ms.Free;
end;
end;
Procedure LoadPictureFromBlob(Picture: TPicture; Blob: TBlobField);
var
ms, ms2: TMemoryStream;
len: Byte;
theClassName: AnsiString;
Graphic: TGraphic;
GraphicClass: TGraphicClass;
begin
ms := TMemoryStream.Create;
Blob.SaveToStream(ms);
ms.Position := 0;
try
ms.ReadBuffer(len, 1);
SetLength(theClassName, len);
if len > 0 then
ms.ReadBuffer(theClassName[1], len);
GraphicClass := TGraphicClass(FindClass(theClassName));
if (GraphicClass <> nil) and (len > 0) then
begin
Graphic := GraphicClass.Create;
ms2 := TMemoryStream.Create;
try
ms2.CopyFrom(ms, ms.Size - len - 1);
ms2.Position := 0;
Graphic.LoadFromStream(ms2);
finally
ms2.Free;
end;
Picture.Assign(Graphic);
end;
finally
ms.Free;
end;
end;
initialization
// you might register others if wished
RegisterClasses([TIcon, TMetafile, TBitmap, TJPEGImage,TPngImage]);
end.