问腾讯实时音视频 setAudioRoute 切换音频路由无效？

if (mAudioRoute == TRTCCloudDef.TRTC_AUDIO_ROUTE_SPEAKER){
    mAudioRoute = TRTCCloudDef.TRTC_AUDIO_ROUTE_EARPIECE;
}else{
    mAudioRoute = TRTCCloudDef.TRTC_AUDIO_ROUTE_SPEAKER;
}
trtcCloud.setAudioRoute(mAudioRoute);