Android 如何在exo player中切换可用曲目格式（HLS）？

player.getCurrentTrackGroups（）.get（0）.formats

我看到这种方法，我可以获得可用格式的数组，但我不知道如何从中选择一种。后端支持不同格式具有不同分辨率的HLS。Exo player会根据网络速度自动选择格式，但我想像在youtube上那样手动选择格式。
[从接受的答案中获取帮助][1]
[took help from the accepted answer][1]
DefaultTrackSelector trackSelector = new DefaultTrackSelector(this);
SimpleExoPlayer player = new SimpleExoPlayer.Builder(this).setTrackSelector(trackSelector).build();

//insert above two lines in your initPlayer() method

//this method does the actual work     
private void applySelection(int trackIndex) {

    int videoRendererIndex = 0;

    MappingTrackSelector.MappedTrackInfo mappedTrackInfo = trackSelector.getCurrentMappedTrackInfo();

    //This logic is to find the find the video renderer index
    for (int i = 0; i < mappedTrackInfo.length; i++) {
        TrackGroupArray trackGroups = mappedTrackInfo.getTrackGroups(i);
        if (trackGroups.length != 0) {
            switch (player.getRendererType(i)) {
                case C.TRACK_TYPE_VIDEO:
                    videoRendererIndex = i;
                    break;
            }
        }

    }
    trackGroups = mappedTrackInfo != null ? mappedTrackInfo.getTrackGroups(videoRendererIndex) : null;
    int groupIndex = 0;//which group has the the formats you want to use, in my case it was 0.
    //You can use the debugger or you can Log the whole trackGroup to see its details.
    DefaultTrackSelector.SelectionOverride override = new DefaultTrackSelector.SelectionOverride(groupIndex, trackIndex);

    parametersBuilder = new DefaultTrackSelector.ParametersBuilder(this);
    if (trackGroups != null) {
        parametersBuilder.setSelectionOverride(videoRendererIndex, trackGroups, override);
        trackSelector.setParameters(parametersBuilder);
    }
}

//incase you want to switch to auto quality select, insert these lines you code
trackSelector.clearSelectionOverride(0,trackGroups);

DefaultTrackSelector trackSelector=新的DefaultTrackSelector（此）；
SimpleExoPlayer=新建SimpleExoPlayer.Builder（this）.setTrackSelector（trackSelector.build（）；
//在initPlayer（）方法中插入上面两行
//这种方法做实际工作
私有void applySelection（int-trackIndex）{
int videorenderindex=0；
MappingTrackSelector.MappedTrackInfo MappedTrackInfo=trackSelector.getCurrentMappedTrackInfo（）；
//此逻辑用于查找视频渲染器索引
对于（int i=0；i