如何在Kotlin中为RecyclerView添加项目分隔线 [英] How to add item divider for RecyclerView in Kotlin

问题描述

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线.我已经创建了ItemDividerDecorator类和xml布局文件，但是我没有连接到回收站视图.

I'm working on an app where I have a list with recyclerview and I want to add a divider for items. I have created the ItemDividerDecorator class and xml layout file but I'm not connecting to recycler view.

我知道如何用Java来做，就像这样:

I know how to do in java, something like this:

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

但是我如何在Kotlin中进行操作，我也尝试在Android Studio中进行转换，但显示了一些错误.这是我的Decorator类:

but how can I do in Kotlin, I also tried to convert it in Android Studio but shows me a couples of errors. Here is my Decorator class:

    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)
        }
    }

感谢您的帮助

推荐答案

对于Kotlin:

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

如果您这样初始化:

private lateint var context:Context

然后在您的onCreateView内

then inside your 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
}

如果您在活动内部使用，则使用

If you're using inside an activity then instead use

applicationContext

applicationContext

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

这篇关于如何在Kotlin中为RecyclerView添加项目分隔线的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！