再次问:这个缩略图程序中,怎样让每个图像都可以接受点击事件? (100分)

  • 主题发起人 主题发起人 yukaikai
  • 开始时间 开始时间
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yukaikai

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以下是程序代码:

{
Thumbnail Browser Example by Boern Ischo (www.b-zone.de)

A very simple example on how to create a thumbnail image browser.
There's a lot of stuff to do to use this for a serious program, but
I thought beginners might be interested in this. You're welcome to
send my any questions or comments on this to bjoern@ischo.de

Public Domain. Feel free to use this code in any way you like.
}



unit Unit1;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
ExtCtrls, FileCtrl, StdCtrls,jpeg;

type
TForm1 = class(TForm)
DriveComboBox1: TDriveComboBox;
DirectoryListBox1: TDirectoryListBox;
ScrollBox1: TScrollBox;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure DirectoryListBox1Change(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

type tbi_thumb=class(tcustomcontrol)
fmypic : tjpegimage;
private
procedure getpic(value:tjpegimage);
public
procedure paint; override;
constructor create(aowner:tcomponent); override;
destructor destroy; override;
published
property pic:tjpegimage write getpic;
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

var buffer_jpeg:tjpegimage;

//a simple class for thumbnails...

constructor tbi_thumb.create(aowner:tcomponent);
begin
inherited;
fmypic:=tjpegimage.create;
end;

destructor tbi_thumb.destroy;
begin
inherited;
fmypic.free;
end;

procedure tbi_thumb.getpic(value:tjpegimage);
begin
fmypic.scale:=jshalf;
fmypic.assign(value);
fmypic.dibneeded;
end;

procedure tbi_thumb.paint;
var arect : trect;
ratio : single;
begin
arect:=clientrect;
canvas.stretchdraw(arect,fmypic);
frame3d(canvas,arect,clblack,clwhite,2);
end;

//*<----------------------------------------------------


procedure TForm1.FormCreate(Sender: TObject);
begin
buffer_jpeg:=tjpegimage.create;
buffer_jpeg.Performance:=jpbestspeed;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
buffer_jpeg.free;
while scrollbox1.ComponentCount>0 do
scrollbox1.components[0].free;
end;

procedure TForm1.DirectoryListBox1Change(Sender: TObject);
var i,x,y : integer;
anewthumb : tbi_thumb;
foundlist : tstringlist;
sr : TSearchRec;

begin
foundlist:=tstringlist.create;

try

//look for jpg files
if FindFirst(directorylistbox1.Directory+'/*.jpg', faAnyFile, sr) = 0 then
begin
foundlist.add(sr.name);
while FindNext(sr) = 0 do
foundlist.add(sr.name);
FindClose(sr);
end;

x:=0;
y:=0;

//create the thumbnails
for i:=0 to FoundList.count-1 do
begin
anewthumb:=tbi_thumb.create(self);
buffer_jpeg.loadfromfile(foundlist);
with anewthumb do begin
pic:=buffer_jpeg;
parent:=scrollbox1;
left:=x;
top:=y;
width:=120;
height:=90;
visible:=true;
inc(x,122);
if x>244 then
begin x:=0; inc(y,92); end;
application.processmessages;
end;
end;

finally foundlist.free; end;

end;

end.
 
constructor tbi_thumb.create(aowner:tcomponent);
begin
inherited;
controlstyle := controlstyle and <Click> //好像是这个东东吧
fmypic:=tjpegimage.create;
end;
你还要为这个控件声明一个单击事件,然后在缩略图新建时将这个单击事件指向用户定义
的事件就行了
 
查ControlStyle,ControlState,ComponentState?这三项内容的帮助,以后就不会再遇到这类问题了
 
多人接受答案了。
 
还是不太明白,哪位可以说说吗?

 
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