Kotlin: Recycler View Choppy

Question

我的适配器正确地将图像应用到 RecyclerView 并正确滚动...直到我添加大量项目。然后它变得相当不稳定，我知道这是我的方法的问题。请看下面的代码：

class FragmentMenuViewAdapter(private val menuItems: ArrayList<MenuItemModel>, private val clickListener: (MenuItemModel) -> Unit) : RecyclerView.Adapter<FragmentMenuViewAdapter.CustomViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder {

        val policy = StrictMode.ThreadPolicy.Builder().permitAll().build()
        StrictMode.setThreadPolicy(policy)

        val layoutInflater = LayoutInflater.from(parent.context)
        val cellForRow = layoutInflater.inflate(R.layout.recyclerview_list_items, parent, false)
        return CustomViewHolder(cellForRow)
    }

    override fun getItemCount(): Int {

        return menuItems.size
    }

    override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {

        var menuItemIconURI = RouteManager.mAppModel?.resourcesURL + menuItems[position].icon

        menuItemIconURI = menuItemIconURI.replace("\$platform", "iOS")
        menuItemIconURI = menuItemIconURI.replace("\$scale", "@3x")

        val inputStream = URL(menuItemIconURI).openStream()
        holder.view.menuButton.setImageBitmap(BitmapFactory.decodeStream(inputStream))
        holder.bind(menuItems[position], clickListener)
    }

class CustomViewHolder(val view: View): RecyclerView.ViewHolder(view) {

        fun bind(menuItem: MenuItemModel, clickListener: (MenuItemModel) -> Unit) {
            view.setOnClickListener{clickListener(menuItem)}
        }
    }
}

图片正在通过 URL 链接设置。我有它的工作，但我怀疑我在某个地方犯了一个新手错误，或者只是采取了错误的方法。任何关于如何调整我的代码的建议将不胜感激。

Answer 1

我认为问题来自在主线程中解码位图图像。尝试改用Glide。它可以帮助我们在需要时异步加载图像。例如，如果你想快速滚动RecyclerView，它不需要解码和显示所有图像。此外，它还有一个缓存机制，让这个过程更加顺畅。

build.gradle

dependencies {
    implementation 'com.github.bumptech.glide:glide:4.7.1'
}

FragmentMenuViewAdapter.kt

override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {

    var menuItemIconURI = RouteManager.mAppModel?.resourcesURL + menuItems[position].icon

    menuItemIconURI = menuItemIconURI.replace("\$platform", "iOS")
    menuItemIconURI = menuItemIconURI.replace("\$scale", "@3x")

    Glide.with(holder.view.menuButton.context)
        .load(menuItemIconURI)
        .into(holder.view.menuButton)

    holder.bind(menuItems[position], clickListener)
}