android - 如何在 Kotlin 中为 RecyclerView 添加项目分隔符

Question

我正在开发一个应用程序，其中有一个带有 recyclerview 的列表，我想为项目添加一个分隔符。我已经创建了 ItemDividerDecorator 类和 xml 布局文件，但我没有连接到回收器 View 。

我知道如何在java中做，像这样:

recyclerView.addItemDecoration(
                new DividerItemDecoration(ContextCompat.getDrawable(getApplicationContext(),
                        R.drawable.item_separator)));

但我怎么能在 Kotlin 中做，我也尝试在 Android Studio 中转换它，但显示了几个错误。这是我的装饰类:

    private val mdivider:Drawable
    init{
        this.mdivider = mdivider
    }
    override fun onDrawOver(canvas: Canvas, parent:RecyclerView, state:RecyclerView.State) {
        val left = parent.getPaddingLeft()
        val right = parent.getWidth() - parent.getPaddingRight()
        val childCount = parent.getChildCount()
        for (i in 0 until childCount)
        {
            val child = parent.getChildAt(i)
            val params = child.getLayoutParams() as RecyclerView.LayoutParams
            val top = child.getBottom() + params.bottomMargin
            val bottom = top + mdivider.getIntrinsicHeight()
            mdivider.setBounds(left, top, right, bottom)
            mdivider.draw(canvas)
        }
    }

任何帮助表示赞赏

Answer 1

对于 Kotlin :

 recycler_view.addItemDecoration(
            DividerItemDecoration(
                context,
                LinearLayoutManager.HORIZONTAL
            )
        )

如果你这样初始化:

private lateint var context:Context

然后在你的 onCreateView

 override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    // Intialize context here 
    context = parent.context()
    rootView = container?.inflateView(layoutToInflate) ?: View(context)
    onFragmentCreated(rootView)
    return rootView
}

如果您在 Activity 中使用，则改为使用

applicationContext

val decorator = DividerItemDecoration(applicationContext, LinearLayoutManager.VERTICAL)
            decorator.setDrawable(ContextCompat.getDrawable(applicationContext, R.drawable.file)!!)
            recycler_view.addItemDecoration(decorator)