从网站上下载图片显示到image中
var
MyStream:Tmemorystream;
p:Tjpegimage;
begin
MyStream:=Tmemorystream.Create;
try
IdHTTP1.Get('http://photocdn.sohu.com/20061102/Img246150744.jpg',MyStream);
MyStream.Seek(0,soFromBeginning);
//如果类型不确定，可以通过判断流的前三个字节来判断图片类型
//bmp是：42 4D 36 jpg是：FF D8 FF
p:=Tjpegimage.Create;
p.LoadFromStream(MyStream);
image2.Picture.Bitmap.Assign(p);
except
Showmessage('网络出错!');
end;
p.Free;
MyStream.Free;
