Delphi-从TImageList获取位图 [英] Delphi - get bitmap from a TImageList

问题描述

我正在将图像添加到此处的图像列表-在运行时使用Delphi XE将png图像添加到图像列表中。从此列表中获取位图并将其保存到硬盘驱动器时，会出现问题。

I'm adding an image to an imagelist like here - Add a png image to a imagelist in runtime using Delphi XE. The problem occurs when getting an bitmap from this list and saving it to the hard drive.

bmp:=tbitmap.create;
imagelist.getbitmap(0,bmp);
bmp.savetofile()

这种情况出现在很多白色bmp文件中，有些带有'图片'。

this occurs in a lot of white bmp files and several with 'image'. it should be extremely easily but I can not understand what is wrong.

LE：示例更多是伪代码。下面是

LE: the example was more as pseudo-code.code bellow:

填充列表

   FImageList := TImageList.Create(nil);
   FImageList.Masked:=false;
   FImageList.ColorDepth:=cd32bit;
   FImageList.SetSize(32,32);//I am sure that all images are 32x32
   while not dsTemp.eof do//dstemp is a Tdatasetdescendant
    begin
     ststream := dsTemp.CreateBlobStream(dsTemp.FieldByName('FLAG'), bmRead);

     pngImage := TPngImage.Create;
     pngImage.LoadFromStream(ststream);

     btBitmap := TBitmap.Create;
     btBitmap.PixelFormat := pf32bit;
     btBitmap.Width := pngImage.Width ;
     btBitmap.Height := pngImage.Height ;
     pngImage.AssignTo(btBitmap);
     btBitmap.AlphaFormat:=afIgnored;

     res := FImageList.Add(btBitmap,nil);
//     pngImage.savetofile('C:\a\'+inttostr(res)+'.png');-works. image is ok
//     btBitmap.savetofile('C:\a\'+inttostr(res)+'.bmp');-works. image is ok
     dsTemp.Next;
     freeandnil(btBitmap);
     freeandnil(pngImage);
    end;

加载位图的问题

 for iPos := 0 to FImageList.Count-1 do
  begin
     btBitmap := tbitmap.create;
     FImageList.GetBitmap(iPos,btBitmap);
     btBitmap.savetofile('C:\a\'+inttostr(iPos)+'thr.bmp');//creates the bitmap, but it is white
  end;

在问题关闭后编辑：请更多投票！谢谢

Edit after the question was closed: more downvotes please! Thanks

推荐答案

如果您能为无法使用的图片举例，肯定会有所帮助。同时，您可以尝试使用以下代码：

It would definitely help if you could give an example for the images that dont't work. Meanwhile you can try playing around with this code:

bmp.PixelFormat := pf32bit;
bmp.AlphaFormat := afDefined;
ImageList.GetBitmap(0, bmp);

这篇关于Delphi-从TImageList获取位图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！