native层如何访问rawfile的二进制文件

let resourceManager = getContext(this).resourceManagerawait; 
napiTest.openRawfile(resourceManager); 

static napi_value OpenRawFile(napi_env env, napi_callback_info info) { 
    size_t argc = 1; 
    napi_value args[1] = {nullptr}; 
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr); 
 
    NativeResourceManager *nativeRm = OH_ResourceManager_InitNativeResourceManager(env, args[0]); 
    RawFile *rawFile = OH_ResourceManager_OpenRawFile(nativeRm, "your rawfile name"); 
    RawFileDescriptor descriptor; 
    bool b = OH_ResourceManager_GetRawFileDescriptor(rawFile, descriptor); 
 
    napi_value napi_value_size; 
    napi_create_int32(env, descriptor.length, &napi_value_size); 
 
    return napi_value_size; 
}