선택된 항목을 맨 위에 표시하려면 RecyclerView를 스크롤하십시오.

선택된 항목을 맨 위에 표시하려면 RecyclerView를 스크롤하십시오.

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RecyclerView선택한 항목을 맨 위에 표시 하기 위해 a를 스크롤하는 방법을 찾고 있습니다.

A의 ListView내가 사용하여 해당 작업을 수행 할 수 있었다 scrollTo(x,y)및 필요를 중심으로 될 수있는 요소의 상단을 받고.

다음과 같은 것 :

@Override
public void onItemClick(View v, int pos){
    mylistView.scrollTo(0, v.getTop());
}

문제는 메서드를 RecyclerView사용할 때 오류가 반환 된다는 scrollTo것입니다.

RecyclerView는 절대 위치로 스크롤을 지원하지 않습니다

a RecyclerView를 스크롤 하여 선택한 항목을보기 상단에 놓을 수 있습니까?

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LinearLayoutManager또는 Staggered를 사용하는 경우 GridLayoutManager각각에는 scrollToPositionWithOffset 메소드가 있으며,이 위치는 시작 위치에서 항목 시작 위치와 위치 오프셋을 가져옵니다. RecyclerView필요한 것을 달성하는 것처럼 보입니다 (오프셋을 0으로 설정) 상단에 맞춰야합니다).

예를 들어 :

//Scroll item 2 to 20 pixels from the top
linearLayoutManager.scrollToPositionWithOffset(2, 20);

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수직 LinearLayout Manager를 찾고 있다면 사용자 정의를 사용하여 부드러운 스크롤을 얻을 수 있습니다 LinearSmoothScroller.

import android.content.Context;
import android.graphics.PointF;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.LinearSmoothScroller;
import android.support.v7.widget.RecyclerView;

public class SnappingLinearLayoutManager extends LinearLayoutManager {

    public SnappingLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state,
                                       int position) {
        RecyclerView.SmoothScroller smoothScroller = new TopSnappedSmoothScroller(recyclerView.getContext());
        smoothScroller.setTargetPosition(position);
        startSmoothScroll(smoothScroller);
    }

    private class TopSnappedSmoothScroller extends LinearSmoothScroller {
        public TopSnappedSmoothScroller(Context context) {
            super(context);

        }

        @Override
        public PointF computeScrollVectorForPosition(int targetPosition) {
            return SnappingLinearLayoutManager.this
                    .computeScrollVectorForPosition(targetPosition);
        }

        @Override
        protected int getVerticalSnapPreference() {
            return SNAP_TO_START;
        }
    }
}

재활용보기에서 레이아웃 관리자의 인스턴스를 사용하면 호출 recyclerView.smoothScrollToPosition(pos);하면 선택한 위치로 부드럽게 스크롤하여 재활용보기 상단으로 이동합니다.

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// 항목 위치 스크롤

linearLayoutManager.scrollToPositionWithOffset(pos, 0);

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전화하면 recyclerview.scrollToPosition(position)됩니다. 괜찮아!

어댑터에서 호출하려면 어댑터에 메소드 getRecyclerview()를 구현하는 것보다 어댑터에 recyclerview의 인스턴스 또는 recyclerview를 포함하는 활동 또는 단편을 갖도록하십시오.

나는 그것이 당신을 도울 수 있기를 바랍니다.

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스피드 레귤레이터와 동일

public class SmoothScrollLinearLayoutManager extends LinearLayoutManager {
private static final float MILLISECONDS_PER_INCH = 110f;
private Context mContext;

public SmoothScrollLinearLayoutManager(Context context,int orientation, boolean reverseLayout) {
    super(context,orientation,reverseLayout);
    mContext = context;
}

@Override
public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state,
                                   int position) {
    RecyclerView.SmoothScroller smoothScroller = new TopSnappedSmoothScroller(recyclerView.getContext()){
        //This controls the direction in which smoothScroll looks for your view
        @Override
        public PointF computeScrollVectorForPosition(int targetPosition) {
            return new PointF(0, 1);
        }

        //This returns the milliseconds it takes to scroll one pixel.
        @Override
        protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
            return MILLISECONDS_PER_INCH / displayMetrics.densityDpi;
        }
    };
    smoothScroller.setTargetPosition(position);
    startSmoothScroll(smoothScroller);
}


private class TopSnappedSmoothScroller extends LinearSmoothScroller {
    public TopSnappedSmoothScroller(Context context) {
        super(context);

    }

    @Override
    public PointF computeScrollVectorForPosition(int targetPosition) {
        return SmoothScrollLinearLayoutManager.this
                .computeScrollVectorForPosition(targetPosition);
    }

    @Override
    protected int getVerticalSnapPreference() {
        return SNAP_TO_START;
    }
}
}

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나를 위해 일한 것을 시원하게 해보십시오!

변수 만들기 private static int displayedposition = 0;

이제 활동에서 RecyclerView의 위치를 ​​찾으십시오.

myRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

                LinearLayoutManager llm = (LinearLayoutManager) myRecyclerView.getLayoutManager();


                displayedposition = llm.findFirstVisibleItemPosition();


            }
        });

이 문장을 원하는 곳에 배치하여 이전 사이트를보기에 표시하십시오.

LinearLayoutManager llm = (LinearLayoutManager) mRecyclerView.getLayoutManager();
        llm.scrollToPositionWithOffset(displayedposition , youList.size());

글쎄, 그것은 나를 위해 잘 작동 \ o /

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버튼을 클릭하면 RecyclerView를 새로 고친 후 스크롤 위치를 복원하기 위해 수행 한 작업 :

if (linearLayoutManager != null) {

    index = linearLayoutManager.findFirstVisibleItemPosition();
    View v = linearLayoutManager.getChildAt(0);
    top = (v == null) ? 0 : (v.getTop() - linearLayoutManager.getPaddingTop());
    Log.d("TAG", "visible position " + " " + index);
}

else{
    index = 0;
}

linearLayoutManager = new LinearLayoutManager(getApplicationContext());
linearLayoutManager.scrollToPositionWithOffset(index, top);

linearLayoutManager 객체를 생성하기 전에 맨 처음부터 보이는 항목의 오프셋을 가져 와서 인스턴스화 한 후 LinearLayoutManager 객체의 scrollToPositionWithOffset을 호출했습니다.

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scroll at particular position
and this helped me alot. by click listener you can get the position in your adapter

layoutmanager.scrollToPosition(int position);

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In my case my RecyclerView have a padding top like this

<android.support.v7.widget.RecyclerView
     ...
     android:paddingTop="100dp"
     android:clipToPadding="false"
/>

Then for scroll a item to top, I need to

recyclerViewLinearLayoutManager.scrollToPositionWithOffset(position, -yourRecyclerView.getPaddingTop());

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I don't know why I didn't find the best answer but its really simple.

recyclerView.smoothScrollToPosition(position);

No errors

Creates Animations

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just call this method simply:

((LinearLayoutManager)recyclerView.getLayoutManager()).scrollToPositionWithOffset(yourItemPosition,0);

instead of:

recyclerView.scrollToPosition(yourItemPosition);

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If you want to scroll automatic without show scroll motion then you need to write following code:

**=> mRecyclerView.getLayoutManager().scrollToPosition(position);**

If you want to display scroll motion then you need to add following code.
=>Step 1: You need to declare SmoothScroller.

RecyclerView.SmoothScroller smoothScroller = new
                LinearSmoothScroller(this.getApplicationContext()) {
                    @Override
                    protected int getVerticalSnapPreference() {
                        return LinearSmoothScroller.SNAP_TO_START;
                    }
                };

=>step 2: You need to add this code any event you want to perform scroll to specific position.
=>First you need to set target position to SmoothScroller.

**smoothScroller.setTargetPosition(position);**

=>Then you need to set SmoothScroller to LayoutManager.
                        **mRecyclerView.getLayoutManager().startSmoothScroll(smoothScroller);**

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I use the code below to smooth-scroll an item (thisView) to the top.
It works also for GridLayoutManager with views of different heights:

View firstView = mRecyclerView.getChildAt(0);
int toY = firstView.getTop();
int firstPosition = mRecyclerView.getChildAdapterPosition(firstView);
View thisView = mRecyclerView.getChildAt(thisPosition - firstPosition);
int fromY = thisView.getTop();

mRecyclerView.smoothScrollBy(0, fromY - toY);

Seems to work good enough for a quick solution.

참고URL : https://stackoverflow.com/questions/26875061/scroll-recyclerview-to-show-selected-item-on-top