iOS airPlay投屏电视实现

- (MPVolumeView *)airPlayBtn {
    if (!_airPlayBtn) {
        CGFloat w = 32;
        _airPlayBtn=[[MPVolumeView alloc] initWithFrame:CGRectMake(20, 20, w, w)];
        [_airPlayBtn setShowsVolumeSlider:NO];
        [_airPlayBtn setShowsRouteButton:YES];
        [_airPlayBtn sizeToFit];
    }
    return _airPlayBtn;
}