背景

我在开发一款商业软件（518抽奖软件：http://www.）的时候，使用了开源的ImageStone图像处理库，并将图片显示的代码封装为一个C++类，可显示透明PNG图片。

H文件

#ifndef _Timg_h_
#define _Timg_h_
class Timg
{
public:
    Timg ();
    ~Timg ();
    void* img;
    BOOL load (const WCHAR* file);
    void unload ();
    BOOL isLoad ();
    void draw (HDC hDc, RECT rc);
    int getWidth ();
    int getHeight ();
    void stretch (int maxSize);
    BOOL save (const WCHAR* file);
};
#endif
                           
CPP文件

#include
#include "_Timg.h"
#include "ImageStone.h"
Timg::Timg ()
{
    img = new FCObjImage();
}
Timg::~Timg ()
{
    delete (FCObjImage*)img;
}
BOOL Timg::load (const WCHAR* file)
{
    if ( ((FCObjImage*)img)->Load(file, NULL) ) {
        if (((FCObjImage*)img)->ColorBits() == 32)
            ((FCObjImage*)img)->ApplyEffect (FCEffectPremultipleAlpha());//透明预处理
        return TRUE;
    }
    return FALSE;
}
BOOL Timg::isLoad ()
{
    return ((FCObjImage*)img)->IsValidImage ();
}
void Timg::unload ()
{
    ((FCObjImage*)img)->Destroy ();
}
void Timg::draw (HDC hDc, RECT rc)
{
    ((FCObjImage*)img)->Draw (hDc, rc);
}
int Timg::getWidth ()
{
    return ((FCObjImage*)img)->Width ();
}
int Timg::getHeight ()
{
    return ((FCObjImage*)img)->Height ();
}
void Timg::stretch (int maxSize)
{
    int w = ((FCObjImage*)img)->Width();
    int h = ((FCObjImage*)img)->Height();
    if (w<=0 || h<=0) return;
    double r;
    if (w >= h) r = (double)maxSize / (double)w;
    else r = (double)maxSize / (double)h;

    ((FCObjImage*)img)->Stretch (w*r, h*r);
}
BOOL Timg::save (const WCHAR* file)
{
    return ((FCObjImage*)img)->Save(file);
}
                           
518抽奖软件下载：http://www.
ImageStone下载：http://www.