一个关于Listview 显示 缩略图的问题 见鬼了

Question

先看看代码 :unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ImgList, StdCtrls, ComCtrls, Jpeg, ExtCtrls;type
  TForm1 = class(TForm)
    ListView1: TListView;
    Button1: TButton;
    ImageList1: TImageList;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;
  FileList: TStringList;implementation{$R *.dfm}
procedure ChangeDir(dir: string);
var
  SearchRec : TSearchRec;
  Attr : integer;
  Found : integer;
  ExtFileName:string;
  temstr:string;
begin
  FileList.Clear;
  temstr:=dir+'\*.*';
  Attr := faAnyFile;
  Found := FindFirst(temstr, Attr, SearchRec);
  while Found = 0 do
  begin
    ExtFileName:=LowerCase(ExtractFileExt(SearchRec.Name));
    if (ExtFileName='.bmp') or (ExtFileName='.jpg') or ((ExtFileName='.jpeg')) then
      FileList.Add(dir+'\'+SearchRec.Name) ;
    Found := FindNext(SearchRec);
  end;
  FindClose(SearchRec);
end;procedure JpgToBmp(const JpgFileName:string;AJpg:TJpegImage;Abmp:Tbitmap);
begin
  try
    AJpg.LoadFromFile(JpgFileName);
    Abmp.Assign(AJpg);
  finally
  end;
end;procedure DrawPanel(canvas:TCanvas; Left,Top,Width,Height: integer; PanelType:integer);
var
  Right,Bottom:integer;
  LeftTopColor,RightBottomColor:TColor;
begin
  if PanelType=1 then begin
    LeftTopColor:=clwhite;
    RightBottomColor:=clgray;
  end
  else begin
    LeftTopColor:=clgray;
    RightBottomColor:=clwhite;
  end;  Right:=Left+width;
  Bottom:=Top+Height;  Canvas.Pen.Width:=1;
  Canvas.Pen.Color:=LeftTopColor;  Canvas.MoveTo(Right,Top);
  Canvas.lineTo(Left,Top);
  Canvas.LineTo(Left,bottom);  Canvas.Pen.Color:=RightBottomColor;
  Canvas.lineTo(Right,Bottom);
  Canvas.lineTo(Right,Top);
end;procedure AddThumbFromFile(FullFileName: string; ImageList: TImageList ) ;
var
  OriginalBmp,ThumbBmp:TBitmap;
  OrignalJpg : TJpegImage ;
  ThumbBmpHeight,
  ThumbBmpTop,
  ThumbBmpWidth,
  ThumbBmpLeft: integer;
begin
  OrignalJpg := TJpegImage.Create ;
  OriginalBmp:= TBitmap.Create ;
  ThumbBmp:= Tbitmap.Create;  JpgToBmp(FullFileName,OrignalJpg,OriginalBmp);  if OriginalBmp.Height>=OriginalBmp.Width then
    begin
    ThumbBmpWidth:= 120*OriginalBmp.Width div OriginalBmp.Height;
    ThumbBmpLeft:= (120-ThumbBmpWidth) div 2 -1;    ThumbBmp.Canvas.Brush.Color :=clBtnFace;
    ThumbBmp.Canvas.FillRect(ThumbBmp.Canvas.ClipRect);    DrawPanel(ThumbBmp.Canvas,0,0,150-1,150-1,1);
    DrawPanel(ThumbBmp.Canvas,9,9,120-1,120-1,2);
    ThumbBmp.Canvas.StretchDraw(Rect(ThumbBmpLeft+9,9,ThumbBmpLeft+ThumbBmpWidth+9,119),
                                OriginalBmp);
    ImageList.Add(ThumbBmp,nil);  //这里出错 invaid image size 怎么回事？？
    end;  OrignalJpg.Free;
  OriginalBmp.Free;
  ThumbBmp.Free;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  I : integer ;
begin
  FileList := TStringList.Create ;
  ImageList1.Height := 150 ;
  ImageList1.Width := 150 ;
  ChangeDir('c:\1\');
  ListView1.Items.BeginUpdate;
  for I:=0 to FileList.Count-1 do begin
    AddThumbFromFile(FileList[I],ImageList1);
    with ListView1.Items.Add do begin
      ImageIndex:=imagelist1.Count-1;
      caption:=ExtractFileName(FileList[I]);
    end;
  end;
  ListView1.Items.EndUpdate;
  FileList.Free ;
end;end.

Answer 1

这是个实验的东西，一个form 一个listview 一个 button
c:\1  下有两个 jpg 文件读这两个文件 显示缩略图在 listview里面 现在运行到 imagelist.add(ThumdBmp,nil); 的时候报错 invaide image size
你可以试一下啊 谢谢了  真见鬼。

Answer 2

你要把 ThumdBmp 的 Width 和 Height 设成 ListView 连的 ImageList里设置的图标的大小。....
b2.Canvas.StretchDraw(RECT(0, 0, 90, 60), bitmapbuffer);  //
....

Answer 3

b2.Width:= ImgList_Album.Width;
b2.Height:= ImgList_Album.Height;
....
b2.Canvas.StretchDraw(RECT(0, 0, 90, 60), bitmapbuffer);  //
....