选择时如何将项目设置为回收站视图的中心

Question

I am using a RecyclerView to display items horizontally. I want to set the selected item to center of the view like this

.

This is how I am doing it:

LinearLayoutManager layoutManager
                = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

Answer 1

I am using a RecyclerView to display items horizontally. I want to set the selected item to center of the view like this

.

This is how I am doing it:

LinearLayoutManager layoutManager
                = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

Answer 2

I am using a RecyclerView to display items horizontally. I want to set the selected item to center of the view like this

.

This is how I am doing it:

LinearLayoutManager layoutManager
                = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

Answer 3

I am using a RecyclerView to display items horizontally. I want to set the selected item to center of the view like this

.

This is how I am doing it:

LinearLayoutManager layoutManager
                = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

Answer 4

I am using a RecyclerView to display items horizontally. I want to set the selected item to center of the view like this

.

This is how I am doing it:

LinearLayoutManager layoutManager
                = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);

Answer 5

Define your custom layout manager as

class CenterLayoutManager : LinearLayoutManager {
    constructor(context: Context) : super(context)
    constructor(context: Context, orientation: Int, reverseLayout: Boolean) : super(context, orientation, reverseLayout)
    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int) : super(context, attrs, defStyleAttr, defStyleRes)

    override fun smoothScrollToPosition(recyclerView: RecyclerView, state: RecyclerView.State, position: Int) {
        val centerSmoothScroller = CenterSmoothScroller(recyclerView.context)
        centerSmoothScroller.targetPosition = position
        startSmoothScroll(centerSmoothScroller)

    }

    private class CenterSmoothScroller(context: Context) : LinearSmoothScroller(context) {
        override fun calculateDtToFit(viewStart: Int, viewEnd: Int, boxStart: Int, boxEnd: Int, snapPreference: Int): Int = (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2)
    }
}

Then assign this layout manager to your recycler view

myRecyclerview.layoutManager =
        CenterLayoutManager(this, LinearLayoutManager.HORIZONTAL, false)

In recyclerview's item onClick method use

myRecyclerview.smoothScrollToPosition(position)

where position should get from onBindViewHolder

Also use LinearSnapHelper as

 val snapHelper = LinearSnapHelper()
    snapHelper.attachToRecyclerView(myRecyclerview)

it will controll scrolling effectively

Also attatch scroll listner to recyclerview to get item at center position

Recyclerview.setOnScrollListener(object:
            RecyclerView.OnScrollListener() {
            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                super.onScrolled(recyclerView, dx, dy)
                var view=recyclerView[0]

            }
        })

check out this stackoverflow answer for more details