图片加密使用xxtea来加密，加密秘钥自己定，思路就是自己使用代码首先将图片加密，在程序中使用的时候，在加载图片资源处再将资源解密

加密代码如下：

首先要加载头文件

2、将图片加密

bool jiamiImg(string inputFileName,string outFileName)
{
    string fileName=FileUtils::getInstance()->fullPathForFilename(inputFileName);
    
    if(fileName.empty())
    {
        return  false;
    }
    
    Data fileData=FileUtils::getInstance()->getDataFromFile(fileName);
    xxtea_long ret_len;
    unsigned char key[100]="lyctianya";
    unsigned char* ret_data= xxtea_encrypt(fileData.getBytes(),(xxtea_long)fileData.getSize(),key,(xxtea_long)strlen("lyctianya"),&ret_len);
    
    if (ret_data==NULL) {
        return false;
    }
    
    FILE*fp=fopen(outFileName.c_str(),"wb+");
    if (fp==NULL) {
        return false;
    }
    fwrite(ret_data,ret_len,1,fp);
    fflush(fp);
    fclose(fp);
    CC_SAFE_DELETE(ret_data);
    
    return true;
    
}

    /*************jiami************/
    /*
    std::string outFileName="/Users/liyongchuang/Desktop/cocosTool/code/myLuaTest/res/jiamiStar.png";
    bool jiamiRet=jiamiImg("Star.png",outFileName.c_str());
    if (jiamiRet) {
        printf("-----success-----\n");
    }
    else
    {
        printf("------false------\n");
    }
     */

5、修改加载图片资源处，并使用解密

修改

加入并修改如下代码：头文件自己加

bool isEndWith(std::string inputStr,std::string endStr)
{
    if (inputStr.empty()||endStr.empty())
    {
        return false;
    }
    std::string newEndStr = inputStr.substr(inputStr.find_last_of("."));
    if (endStr.compare(newEndStr) == 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

bool Image::initWithImageFile(const std::string& path)
{
    bool ret = false;
    _filePath = FileUtils::getInstance()->fullPathForFilename(path);

#ifdef EMSCRIPTEN
    // Emscripten includes a re-implementation of SDL that uses HTML5 canvas
    // operations underneath. Consequently,loading images via IMG_Load (an SDL
    // API) will be a lot faster than running libpng et al as compiled with
    // Emscripten.
    SDL_Surface *iSurf = IMG_Load(fullPath.c_str());

    int size = 4 * (iSurf->w * iSurf->h);
    ret = initWithRawData((const unsigned char*)iSurf->pixels,size,iSurf->w,iSurf->h,8,true);

    unsigned int *tmp = (unsigned int *)_data;
    int nrPixels = iSurf->w * iSurf->h;
    for(int i = 0; i < nrPixels; i++)
    {
        unsigned char *p = _data + i * 4;
        tmp[i] = CC_RGB_PREMULTIPLY_ALPHA( p[0],p[1],p[2],p[3] );
    }

    SDL_FreeSurface(iSurf);
#else
    Data data;
    if (isEndWith(_filePath,".lyc"))
    {
        Data fileData=FileUtils::getInstance()->getDataFromFile(_filePath);
        xxtea_long ret_len;
        unsigned char key[100]="lyctianya";
        unsigned char*ret_data=xxtea_decrypt(fileData.getBytes(),strlen("lyctianya"),&ret_len);
        data.fastSet(ret_data,ret_len);
    }
    else
    {
        data = FileUtils::getInstance()->getDataFromFile(_filePath);
    }

    if (!data.isNull())
    {
        ret = initWithImageData(data.getBytes(),data.getSize());
    }
#endif // EMSCRIPTEN

    return ret;
}

bool Image::initWithImageFileThreadSafe(const std::string& fullpath)
{
    bool ret = false;
    _filePath = fullpath;
    
    Data data;
    if (isEndWith(_filePath,ret_len);
    }
    else
    {
        data = FileUtils::getInstance()->getDataFromFile(_filePath);
    }
    
    if (!data.isNull())
    {
        ret = initWithImageData(data.getBytes(),data.getSize());
    }
    
    return ret;
}

顺便附上单独解密代码：

bool jiemiImg(string jiaMiFileName,string outFileName)
{
    string fileName=FileUtils::getInstance()->fullPathForFilename(jiaMiFileName);
    if (fileName.empty()) {
        return false;
    }
    Data fileData=FileUtils::getInstance()->getDataFromFile(fileName);
    xxtea_long ret_len;
    unsigned char key[100]="lyctianya";
    unsigned char*ret_data=xxtea_decrypt(fileData.getBytes(),&ret_len);
    if (ret_data==NULL) {
        return false;
    }
    FILE*fp=fopen(outFileName.c_str(),fp);
    fflush(fp);
    fclose(fp);
    CC_SAFE_DELETE(ret_data);
    return true;
}

    /*************jiemi************/
    /*
     std::string outFileName="/Users/liyongchuang/Desktop/cocosTool/code/myLuaTest/res/jiemiStar.png";
     bool jiaemiRet=jiemiImg("jiamiStar.png",outFileName.c_str());
     if (jiaemiRet) {
     printf("-----success-----\n");
     }
     else
     {
     printf("------false------\n");
     }
    */

local function main()
    local gameScene=cc.Scene:create()
    local ly=cc.LayerColor:create(cc.c4b(0,255,255))
    gameScene:addChild(ly)
    
    local lb=cc.Label:createWithSystemFont("Hello world","Arial",20)
    ly:addChild(lb)
    lb:setPosition(480,320)

    local sp=cc.Sprite:create("res/jiamiStar.lyc")
    ly:addChild(sp,10)

    sp:setPosition(cc.p(480,280))


    if cc.Director:getInstance():getRunningScene()  then
    	cc.Director:getInstance():replaceScene(gameScene)
    else
    	cc.Director:getInstance():runWithScene(gameScene)
    end


end

顺便提一下，大家有没有发现一个问题，我的一些资源用了没有释放哦！

unsigned char *zipFileData =FileUtils::getInstance()->getFileData(zipFilePath.c_str(),"rb",&size);

free(zipFileData);