如何将 BLOB 流中的任意图像加载到 TImage 中? [英] How to load an arbitrary image from a BLOB stream into a TImage?

问题描述

如果我理解正确，TImage.LoadFromFile 根据文件扩展名确定图片类型.

If I understand it correctly, TImage.LoadFromFile determines the type of picture from the file extension.

有没有办法从带有原始图像的 TBlobStream 中自动检测图像类型?

Is there any way to detect the image type automatically from a TBlobStream with a raw image in it?

我当前的代码:

procedure LoadImageFromStream(AImage: TImage; ADataSet: TDataSet);
var
  Stream: TStream;
begin
  Stream := ADataSet.CreateBlobStream(Field, bmRead);
  try
    AImage.Picture.Graphic.LoadFromStream(Stream);
  finally
    Stream.Free;
  end;
end

推荐答案

见这个 SO answer 用于从标题中检索文件内容.

See this SO answer for file content retrieval from header.

或者您可以使用我们的 TSynPicture 类，它将使用 Gdi+ 库处理所有类型的图片(bmp/gif/tiff/jpg/png)，合二为一单班.所以你的 TPicture 可以是这个独特的类，用于任何类型的图片.与 Jpeg 或 PNG Delphi 单元相比，代码开销更少.

Or you can use our TSynPicture class, which will handle all kind of pictures (bmp/gif/tiff/jpg/png) using Gdi+ library, in one single class. So your TPicture can be this unique class, for any kind of picture. With less code overhead than the Jpeg or PNG Delphi units.

var Pic: TSynPicture;

Pic := TSynPicture.Create;
Pic.LoadFromStream(aStream); // will load bmp/gif/tiff/jpeg/png content
AImage.Picture.Graphic := Pic;
....

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