How to load TppImage from TMemoryStream, graphic type not known til run-time

rbuser

I have a company logo stored in a SQL Server table. The logo is read into a
memory stream when the program starts up.

I also read the type of the logo, bitmap, jpg, gif or wmf.

How do I transfer the contents of the memoryStream to a TppImage at
run-time?

nardmoseley

Try something like this:

var
lImageStream: TMemoryStream;
lGraphicClass: TGraphicClass;


lGraphicClass := TBitmap; {or whatever class}

lImageStream.Position := 0;

lGraphic := lGraphicClass.Create;

lGraphic.LoadFromStream(lImageStream);

myTppImage.Picture.Graphic := lGraphic;

lGraphic.Free;

rbuser

My first try with your example didn't work...

Here's my code:

type
TJCBLOBObject = class (TObject)
ID : integer;
TypeID : smallint;
BLOB : TMemoryStream;
Comment : string;
end;

function loadBlobStreamIntoPicture (BLOBObject : TJCBLOBObject;
Picture : TPicture) : integer;
var
graphicClass : TGraphicClass;
gr : TGraphic;
begin
result := 0;

// The it??? constants are my own, itBitmap is 1, itIcon 2, etc.
case BLOBObject.TypeID of
itBitmap : graphicClass := TBitmap;
itIcon : graphicClass := TIcon;
itMetafile : graphicClass := TMetafile;
itJPG : graphicClass := TJPEGImage;
else graphicClass := nil;
end;

if assigned (graphicClass)
then
begin
// BlobObject.BLOB is the TMemoryStream
BLOBObject.BLOB.position := 0;
gr := graphicClass.create;
try
gr.loadFromStream (BLOBObject.BLOB);
Picture.graphic := gr;
result := BLOBObject.TypeID;
finally
gr.free;
end;
end;
end;

The stream has data, as checked by looking at Blob.size.

I call the routine like this:

loadBlobStreamIntoPicture (licenseeSettings.Logo, imgLogo.picture);

imgLogo is a TppImage.

I tried with bitmap and JPG and neither showed up in the report.

Any help is much appreciated.

rbuser

It's working now...

I had a TppDBImage in for testing and had not changed back to a TppImage.
With the TppImage the code below works fine.