Question

我希望将网络上的图像转换为流（不保存）并将其显示在TImage上。以下代码产生错误：

response := TMemoryStream.Create;
try
   HttpGetBinary('http://www.example-url/example_image.jpg', response);
   Image.Picture.LoadFromStream(response);
finally
   response.Free;
end;

Project -------引发异常类'EReadError'并带有消息：流读错误

这是Synapse库中的函数（在picture.inc中），错误指向：

function TPicFileFormatsList.FindByStreamFormat(Stream: TStream): TGraphicClass;
var
  I: Integer;
begin
  for I := Count - 1 downto 0 do
  begin
    Result := GetFormats(I)^.GraphicClass;
    if Result.IsStreamFormatSupported(Stream) then   // <<<<<< this is the error line
      Exit;
  end;
  Result := nil;
end;

Answer 1

您必须在项目的某处包含JPEGLib单元，以便JPEG图形类得到注册。

uses
  JPEGLib, // to support JPEG
  PNGcomn, // to support PNG
  httpsend;

response := TMemoryStream.Create;
try
   if HttpGetBinary('http://www.example-url/example_image.jpg', response) then
   begin
     response.Seek( 0, soFromBeginning );
     Image.Picture.LoadFromStream( response );
   end;
finally
   response.Free;
end;

从网上获取图像并使用Synapse显示

1 个答案: