下载到本地的图片怎么是黑色的?..急!

Cocos2d-x
#1

http回调时保存的图片:


void ImageHttpAdapter::onResponseListener(long lastLength, vector<char> *buf){
    if(buf != NULL){
//        FileUtils::saveImage2Files(imageUrl, buf);   //方式1
        
        FileUtils::saveImage2SDCard(imageUrl);
        
        CCImage *image = new CCImage();
        image->initWithImageData(buf->data(), buf->size());
        image->saveToFile(FileUtils::getFileRealPath(imageUrl).c_str());    //方式2
        
        CCTexture2D *t2d = new CCTexture2D();
        t2d->initWithImage(image);
        
        image->release();
        (target->*asyncSel)(getPrivateData(), t2d);
    }else{
        (target->*asyncSel)(NULL, NULL);
    }
    
}

方式1:


void FileUtils::saveImage2Files(string url, vector<char> *buffer){
    string fileName = MD5(url).toString() + SUFIX;
    string path = CCFileUtils::sharedFileUtils()->getWritablePath() + DIR_IMAGE;
    
    if(CCFileUtils::sharedFileUtils()->isFileExist(path) == false){
        #if (CC_TARGET_PLATFORM != CC_PLATFORM_WIN32)
            mode_t processMask = umask(0);
            mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IRWXO);
            umask(processMask);
        #endif
    }
    
    path += "/" + fileName;
    
    if(CCFileUtils::sharedFileUtils()->isFileExist(path) == false){
        string buf(buffer->begin(), buffer->end());
        
        FILE *fp = fopen(path.c_str(), "wb+");
        fwrite(buf.c_str(), 1, buffer->size(), fp);
        fclose(fp);
    }
}

读取图片文件:


CCTexture2D* FileUtils::getImageFromFiles(string url){
    CCTexture2D *t2d = NULL;
    do{
        CCImage *image = new CCImage();
        
        bool ret = false;
        if(FileUtils::isFileExist(url) == true){
            ret = image->initWithImageFile(getFileRealPath(url).c_str(), CCImage::kFmtJpg);
            CC_BREAK_IF(!ret);
            CCLog("读取成功");
        }else{
            return NULL;
        }
        
        t2d = new CCTexture2D();
        t2d->initWithImage(image);
        
        image->release();
        
        break;
        
    }while (0);
    return t2d;
}

无论是用方式1, 还是方式2, 下载到手机里的图片, 大小正常, 但是图片就是黑色的, 如果直接加载网络图片就能正常显示.
读取出来的图片也是黑色的…

请问这是怎么回事啊???

奇怪的是:
1.直接用手机打开图片是黑色的
2.把图片拷贝电脑,再打开,正常.
3.在ios模拟器上,无论保存还是读取, 正常
4.用android代码加载到布局里, 正常
android代码:


    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);    
        
                ....
        
        File root = new File(getFilesDir() + File.separator + "image");
        root.listFiles().getAbsolutePath();
        ImageView iv = new ImageView(act);
        iv.setImageBitmap(BitmapFactory.decodeFile(root.listFiles().getAbsolutePath()));
        setContentView(iv);
    }

另:
cocos2dx版本2.2.5
用的android真机测试, 版本4.4.4