napi_get_named_property
napi_status napi_get_named_property(napi_env env,
                                    napi_value object,
                                    const char* utf8Name,
                                    napi_value* result); - 
[in] env:调用 Node-API 调用的环境。¥
[in] env: The environment that the Node-API call is invoked under. - 
[in] object:从中检索属性的对象。¥
[in] object: The object from which to retrieve the property. - 
[in] utf8Name:要获取的属性的名称。¥
[in] utf8Name: The name of the property to get. - 
[out] result:属性的值。¥
[out] result: The value of the property. 
如果 API 成功,则返回 napi_ok。
¥Returns napi_ok if the API succeeded.
此方法等效于使用从作为 utf8Name 传入的字符串创建的 napi_value 调用 napi_get_property。
¥This method is equivalent to calling napi_get_property with a napi_value
created from the string passed in as utf8Name.