Question

我有这个。...

class MainActivity : AppCompatActivity() {
    private var player: SimpleExoPlayer? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        if (cache == null) {
            cache = SimpleCache(File(cacheDir, "media"), LeastRecentlyUsedCacheEvictor(MAX_PREVIEW_CACHE_SIZE_IN_BYTES))
        }
        setContentView(R.layout.activity_main)
    }

    override fun onStart() {
        super.onStart()
        playVideo()
    }

    private fun playVideo() {
        player = ExoPlayerFactory.newSimpleInstance(this@MainActivity, DefaultTrackSelector())
        playerView.player = player
        player!!.volume = 1f
        player!!.playWhenReady = true
        player!!.repeatMode = Player.REPEAT_MODE_ALL
        player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/240/big_buck_bunny_240p_20mb.mkv", cache!!)
//        player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/720/big_buck_bunny_720p_1mb.mkv", cache!!)
//        player!!.playVideoFromUrl(this, "https://sample-videos.com/video123/mkv/720/big_buck_bunny_720p_1mb.mkv")
//        player!!.playRawVideo(this,R.raw.videoplayback)
    }

    override fun onStop() {
        super.onStop()
        playerView.player = null
        player!!.release()
        player = null
    }

    companion object {
        const val MAX_PREVIEW_CACHE_SIZE_IN_BYTES = 20L * 1024L * 1024L
        var cache: com.google.android.exoplayer2.upstream.cache.Cache? = null

        @JvmStatic
        fun getUserAgent(context: Context): String {
            val packageManager = context.packageManager
            val info = packageManager.getPackageInfo(context.packageName, 0)
            val appName = info.applicationInfo.loadLabel(packageManager).toString()
            return Util.getUserAgent(context, appName)
        }
    }

    fun SimpleExoPlayer.playRawVideo(context: Context, @RawRes rawVideoRes: Int) {
        val dataSpec = DataSpec(RawResourceDataSource.buildRawResourceUri(rawVideoRes))
        val rawResourceDataSource = RawResourceDataSource(context)
        rawResourceDataSource.open(dataSpec)
        val factory: DataSource.Factory = DataSource.Factory { rawResourceDataSource }
        prepare(LoopingMediaSource(ExtractorMediaSource.Factory(factory).createMediaSource(rawResourceDataSource.uri)))
    }

    fun SimpleExoPlayer.playVideoFromUrl(context: Context, url: String, cache: Cache? = null) = playVideoFromUri(context, Uri.parse(url), cache)

    fun SimpleExoPlayer.playVideoFile(context: Context, file: File) = playVideoFromUri(context, Uri.fromFile(file))

    fun SimpleExoPlayer.playVideoFromUri(context: Context, uri: Uri, cache: Cache? = null) {
        val factory = if (cache != null)
            CacheDataSourceFactory(cache, DefaultHttpDataSourceFactory(getUserAgent(context)))
        else
            DefaultDataSourceFactory(context, MainActivity.getUserAgent(context))
        val mediaSource = ExtractorMediaSource.Factory(factory).createMediaSource(uri)
        prepare(mediaSource)
    }
}

我需要使不起作用的代码起作用。实际上，警报行执行得很好，所以这意味着可以很好地进行迭代。但是，这无法呈现结果。有任何线索吗？

我只是将工作代码演示了，无需过滤器即可正常工作。有什么我没有得到的吗？

Answer 1

实际上，您的代码经过一些更改即可正常运行，如下面的演示代码所示。也许您可以查看所有组件，然后尝试使用以下组件。

 <View>
     {
        this.props.events.data.data.filter(flt =>
             flt.location.toLowerCase().includes(this.state.searchText.toLowerCase()))
             .map(item => {
                 alert(item)
                 return (<View key={'ev' + item.id}>
                     <Text>{item.location}</Text>
                 </View>)
             })
     }
 </View>

使用react native过滤器的渲染结果

1 个答案: