Hi
if facebook app in not installed then else block of below code will execute and share photo.
FacebookAgent::FBInfo params;
params.insert(std::make_pair("dialog", "sharePhoto"));
params.insert(std::make_pair("photo", outputFile));
//param required for else block only
params.insert(std::make_pair("name", "My Game"));
params.insert(std::make_pair("caption", "New Coocs2dx game"));
params.insert(std::make_pair("description", "My Game! Built buy cocos2dx."));
params.insert(std::make_pair("link", "http://www.cocos2d-x.org"));
params.insert(std::make_pair("picture", "http://files.cocos2d-x.org/images/orgsite/logo.png"));
if (FacebookAgent::getInstance()->canPresentDialogWithParams(params))
{
//this will execute if facebook app is installed on device
FacebookAgent::getInstance()->dialog(params, [=](int ret ,std::string& msg)
{
CCLOG("%s", msg.c_str());
});
}
else
{
//this will execute if facebook app is not installed in device
FacebookAgent::getInstance()->share(params, [=](int ret ,std::string& msg)
{
CCLOG("%s", msg.c_str());
});
}