void AndroidManager::screenShot(const char* str){
CCSize size = CCDirector::sharedDirector()->getWinSize();
CCRenderTexture* pScreen = CCRenderTexture::create(size.width,size.height);
CCScene* pCurScene = CCDirector::sharedDirector()->getRunningScene();
pScreen->begin();
pCurScene->visit();
pScreen->end();
CCImage* img=pScreen->newCCImage();
img->autorelease();
img->saveToFile(str);
pScreen->cleanup();
}