glide recyclerview集成的进展如何？

Question

我只是尝试使用glide recyclerview集成并阅读有关它的文档,它说:" RecyclerView集成库使您的应用程序中可以使用RecyclerViewPreloader .RecyclerViewPreloader可以在用户在RecyclerView中滚动的位置之前自动加载图像 ",但是我没有意识到滑翔回收视图集成和滑行之间有什么区别,请说明滑行回收视图集成的进展是什么？我怎么能看出差异？

这是我的代码:

GlideModule.kt

@GlideModule
class GlideModule : AppGlideModule() {
    override fun applyOptions(context: Context?, builder: GlideBuilder?) {
        val requestOp = RequestOptions.noAnimation()
                .priority(Priority.LOW)
        builder?.setDefaultRequestOptions(requestOp)
                ?.setLogLevel(Log.VERBOSE)
        super.applyOptions(context, builder)
    }

    // Disable manifest parsing to avoid adding similar modules twice.
    override fun isManifestParsingEnabled(): Boolean {
        return false
    }
}

MyPreloadModelProvide.kt

class MyPreloadModelProvide(val listUrls: List<String>, val context: Context) : PreloadModelProvider<Any> {
    override fun getPreloadItems(position: Int): MutableList<Any> {
        val url = listUrls.get(position)
        if (TextUtils.isEmpty(url)) {
            return Collections.emptyList();
        }
        return Collections.singletonList(url);
    }

    override fun getPreloadRequestBuilder(url: Any?): RequestBuilder<*>? {
        return GlideApp.with(context)
                .load(url)
    }

}

MyAdapter.kt

class MyAdapter(val listUrl: List<String>, val context: Context) : RecyclerView.Adapter<MyViewHolder>() {
    override fun getItemCount(): Int = listUrl.size

    @SuppressLint("CheckResult")
    override fun onBindViewHolder(holder: MyViewHolder?, position: Int) {

        GlideApp.with(context)
                .load(listUrl[position])
                .into(holder?.imageView)

        holder?.imageView?.setOnClickListener { Toast.makeText(context, listUrl[position], Toast.LENGTH_LONG).show() }
    }

    override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): MyViewHolder = MyViewHolder(LayoutInflater.from(parent?.context).inflate(R.layout.item, parent, false))
}

class MyViewHolder(view: View?) : RecyclerView.ViewHolder(view) {
    var imageView: ImageView

    init {
        imageView = view!!.findViewById(R.id.img)
    }
}

MainActivity.kt

class MainActivity : AppCompatActivity() {

    private lateinit var preloadSizeProvider: ViewPreloadSizeProvider<Any>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // glide
        var listUrls = listOf(
                "https://img.pokemondb.net/artwork/bulbasaur.jpg",
                "https://img.pokemondb.net/artwork/ivysaur.jpg",
                "https://img.pokemondb.net/artwork/komala.jpg",
                "https://img.pokemondb.net/artwork/turtonator.jpg",
                "https://img.pokemondb.net/artwork/togedemaru.jpg",
                "https://img.pokemondb.net/artwork/mimikyu.jpg",
                "https://img.pokemondb.net/artwork/nihilego.jpg",
                "https://img.pokemondb.net/artwork/buzzwole.jpg",
                "https://img.pokemondb.net/artwork/pheromosa.jpg",
                "https://img.pokemondb.net/artwork/xurkitree.jpg",
                "https://img.pokemondb.net/artwork/celesteela.jpg",
                "https://img.pokemondb.net/artwork/kartana.jpg",
                "https://img.pokemondb.net/artwork/guzzlord.jpg",
                "https://img.pokemondb.net/artwork/necrozma.jpg",
                "https://img.pokemondb.net/artwork/magearna.jpg",
                "https://img.pokemondb.net/artwork/marshadow.jpg"
        )

        preloadSizeProvider = ViewPreloadSizeProvider<Any>()
        val modelProvider = MyPreloadModelProvide(listUrls, this)
        val preloader = RecyclerViewPreloader(GlideApp.with(this), modelProvider, preloadSizeProvider, 2 /*maxPreload*/)

        // recycler view
        recycler_view.layoutManager = LinearLayoutManager(this)
        recycler_view.setHasFixedSize(true)
        recycler_view.adapter = MyAdapter(listUrls, this)

        // THERE ARE NO DIFFERENCES IF I COMMENT THIS LINE
        recycler_view.addOnScrollListener(preloader)
    }
}

如果我评论这一行,那就没有什么不同了 recycler_view.addOnScrollListener(preloader)

Answer 1

集成RecyclerView库使这些RecyclerViewPreloader可以在您的应用程序中使用。
并且RecyclerViewPreloader可以在用户滚动的位置之前自动加载图像RecyclerView。

结合正确的图像大小和有效的磁盘缓存策略，该库可以通过确保用户即将到达的图像已经在内存中来显着减少用户在滚动图像列表时看到的加载图块/指示器的数量。

要使用RecyclerView集成库，请在文件中添加对其的依赖项build.gradle：

compile ("com.github.bumptech.glide:recyclerview-integration:4.4.0") {
  /*Excludes the support library 
    because it's already included by Glide.*/
  transitive = false
}