Android는 gridlayoutmanager를 사용하여 recyclerview의 마지막 요소 아래에 간격을 추가합니다.

Android는 gridlayoutmanager를 사용하여 recyclerview의 마지막 요소 아래에 간격을 추가합니다.

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나는 마지막 요소 행 아래에 간격을 추가하려고하고 RecyclerView와 GridLayoutManager. ItemDecoration마지막 요소가 다음과 같을 때 하단 패딩과 함께이 목적을 위해 사용자 정의 를 사용 했습니다.

public class SpaceItemDecoration extends RecyclerView.ItemDecoration {
private int space;
private int bottomSpace = 0;

public SpaceItemDecoration(int space, int bottomSpace) {
    this.space = space;
    this.bottomSpace = bottomSpace;
}

public SpaceItemDecoration(int space) {
    this.space = space;
    this.bottomSpace = 0;
}

@Override
public void getItemOffsets(Rect outRect, View view,
                           RecyclerView parent, RecyclerView.State state) {

    int childCount = parent.getChildCount();
    final int itemPosition = parent.getChildAdapterPosition(view);
    final int itemCount = state.getItemCount();

    outRect.left = space;
    outRect.right = space;
    outRect.bottom = space;
    outRect.top = space;

    if (itemCount > 0 && itemPosition == itemCount - 1) {
        outRect.bottom = bottomSpace;
    }
}
}

그러나이 방법의 문제점은 마지막 행의 그리드에서 요소 높이가 엉망이라는 것입니다. GridLayoutManager왼쪽 간격을 기준으로 요소의 높이를 변경 한다고 생각합니다 . 이를 달성하는 올바른 방법은 무엇입니까?

이것은 LinearLayoutManager. GridLayoutManager문제의 경우에만 .

FAB아래쪽에있는 항목이 있고 위쪽으로 스크롤 FAB하여 볼 수 있도록 마지막 행에 항목이 필요한 경우 매우 유용합니다 .

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이 문제에 대한 해결책은 GridLayoutManager의 SpanSizeLookup을 덮어 쓰는 것입니다.

RecylerView를 팽창시키는 Activity 또는 Fragment에서 GridlayoutManager를 변경해야합니다.

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //your code 
    recyclerView.addItemDecoration(new PhotoGridMarginDecoration(context));

    // SPAN_COUNT is the number of columns in the Grid View
    GridLayoutManager gridLayoutManager = new GridLayoutManager(context, SPAN_COUNT);

    // With the help of this method you can set span for every type of view
    gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            if (list.get(position).getType() == TYPE_HEADER) {
                // Will consume the whole width
                return gridLayoutManager.getSpanCount();
            } else if (list.get(position).getType() == TYPE_CONTENT) {
                // will consume only one part of the SPAN_COUNT
                return 1;
            } else if(list.get(position).getType() == TYPE_FOOTER) {
                // Will consume the whole width
                // Will take care of spaces to be left,
                // if the number of views in a row is not equal to 4
                return gridLayoutManager.getSpanCount();
            }
            return gridLayoutManager.getSpanCount();
        }
    });
    recyclerView.setLayoutManager(gridLayoutManager);
}

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패딩을 추가하고 android:clipToPadding="false"

<RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="8dp"
    android:clipToPadding="false" />

이 멋진 답변 덕분에 !

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아래 코드를 사용하여 그리드보기에서 첫 번째 및 마지막 행을 감지하고 이에 따라 상단 및 하단 오프셋을 설정할 수 있습니다.

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, State state) {
    LayoutParams params = (LayoutParams) view.getLayoutParams();
    int pos = params.getViewLayoutPosition();
    int spanCount = mGridLayoutManager.getSpanCount();

    boolean isFirstRow = pos < spanCount;
    boolean isLastRow = state.getItemCount() - 1 - pos < spanCount;

    if (isFirstRow) {
      outRect.top = top offset value here
    }

    if (isLastRow) {
      outRect.bottom = bottom offset value here
    }
}

// you also need to keep reference to GridLayoutManager to know the span count
private final GridLayoutManager mGridLayoutManager;

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할 수있는 일은 recyclerview에 빈 바닥 글을 추가하는 것입니다. 패딩은 바닥 글의 크기입니다.

@Override
public Holder onCreateViewHolder( ViewGroup parent, int viewType) {
    if (viewType == FOOTER) {
        return new FooterHolder();
    }
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
    return new Holder(view);
}

@Override
public void onBindViewHolder(final Holder holder, final int position) {
    //if footer
    if (position == items.getSize() - 1) {
    //do nothing
        return;
    }
    //do regular object bindding

}

@Override
public int getItemViewType(int position) {
    return (position == items.getSize() - 1) ? FOOTER : ITEM_VIEW_TYPE_ITEM;
}

@Override
public int getItemCount() {
    //add one for the footer
    return items.size() + 1;
}

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이와 같은 경우에는 ItemDecoration을 사용하여 해결하는 것이 좋습니다.

public class ListSpacingDecoration extends RecyclerView.ItemDecoration {

  private static final int VERTICAL = OrientationHelper.VERTICAL;

  private int orientation = -1;
  private int spanCount = -1;
  private int spacing;


  public ListSpacingDecoration(Context context, @DimenRes int spacingDimen) {

    spacing = context.getResources().getDimensionPixelSize(spacingDimen);
  }

  public ListSpacingDecoration(int spacingPx) {

    spacing = spacingPx;
  }

  @Override
  public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

    super.getItemOffsets(outRect, view, parent, state);

    if (orientation == -1) {
        orientation = getOrientation(parent);
    }

    if (spanCount == -1) {
        spanCount = getTotalSpan(parent);
    }

    int childCount = parent.getLayoutManager().getItemCount();
    int childIndex = parent.getChildAdapterPosition(view);

    int itemSpanSize = getItemSpanSize(parent, childIndex);
    int spanIndex = getItemSpanIndex(parent, childIndex);

    /* INVALID SPAN */
    if (spanCount < 1) return;

    setSpacings(outRect, parent, childCount, childIndex, itemSpanSize, spanIndex);
  }

  protected void setSpacings(Rect outRect, RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {

    if (isBottomEdge(parent, childCount, childIndex, itemSpanSize, spanIndex)) {
        outRect.bottom = spacing;
    }
  }

  @SuppressWarnings("all")
  protected int getTotalSpan(RecyclerView parent) {

    RecyclerView.LayoutManager mgr = parent.getLayoutManager();
    if (mgr instanceof GridLayoutManager) {
        return ((GridLayoutManager) mgr).getSpanCount();
    } else if (mgr instanceof StaggeredGridLayoutManager) {
        return ((StaggeredGridLayoutManager) mgr).getSpanCount();
    } else if (mgr instanceof LinearLayoutManager) {
        return 1;
    }

    return -1;
  }

  @SuppressWarnings("all")
  protected int getItemSpanSize(RecyclerView parent, int childIndex) {

    RecyclerView.LayoutManager mgr = parent.getLayoutManager();
    if (mgr instanceof GridLayoutManager) {
        return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanSize(childIndex);
    } else if (mgr instanceof StaggeredGridLayoutManager) {
        return 1;
    } else if (mgr instanceof LinearLayoutManager) {
        return 1;
    }

    return -1;
  }

  @SuppressWarnings("all")
  protected int getItemSpanIndex(RecyclerView parent, int childIndex) {

    RecyclerView.LayoutManager mgr = parent.getLayoutManager();
    if (mgr instanceof GridLayoutManager) {
        return ((GridLayoutManager) mgr).getSpanSizeLookup().getSpanIndex(childIndex, spanCount);
    } else if (mgr instanceof StaggeredGridLayoutManager) {
        return childIndex % spanCount;
    } else if (mgr instanceof LinearLayoutManager) {
        return 0;
    }

    return -1;
  }

  @SuppressWarnings("all")
  protected int getOrientation(RecyclerView parent) {

    RecyclerView.LayoutManager mgr = parent.getLayoutManager();
    if (mgr instanceof LinearLayoutManager) {
        return ((LinearLayoutManager) mgr).getOrientation();
    } else if (mgr instanceof GridLayoutManager) {
        return ((GridLayoutManager) mgr).getOrientation();
    } else if (mgr instanceof StaggeredGridLayoutManager) {
        return ((StaggeredGridLayoutManager) mgr).getOrientation();
    }

    return VERTICAL;
  }

  protected boolean isBottomEdge(RecyclerView parent, int childCount, int childIndex, int itemSpanSize, int spanIndex) {

    if (orientation == VERTICAL) {

        return isLastItemEdgeValid((childIndex >= childCount - spanCount), parent, childCount, childIndex, spanIndex);

    } else {

        return (spanIndex + itemSpanSize) == spanCount;
    }
  }

  protected boolean isLastItemEdgeValid(boolean isOneOfLastItems, RecyclerView parent, int childCount, int childIndex, int spanIndex) {

    int totalSpanRemaining = 0;
    if (isOneOfLastItems) {
        for (int i = childIndex; i < childCount; i++) {
            totalSpanRemaining = totalSpanRemaining + getItemSpanSize(parent, i);
        }
    }

    return isOneOfLastItems && (totalSpanRemaining <= spanCount - spanIndex);
  }
}

나는 내 원래의 대답에서 편집 복사 여기에 동일한 간격에 대한 사실이지만이 같은 개념입니다.

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소스 코드에서 DividerItemDecoration.java를 예로 들어

for (int i = 0; i < childCount; i++)

와

for (int i = 0; i < childCount - 1; i++)

drawVertical () 및 drawHorizontal ()

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Should use Decoration In Recycler View for bottom margin in case of the last item only

recyclerView.addItemDecoration(MemberItemDecoration())

public class MemberItemDecoration extends RecyclerView.ItemDecoration {

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        // only for the last one
        if (parent.getChildAdapterPosition(view) == parent.getAdapter().getItemCount() - 1) {
            outRect.bottom = 50/* set your margin here */;
        }
    }
}

참고URL : https://stackoverflow.com/questions/30866106/android-add-spacing-below-last-element-in-recyclerview-with-gridlayoutmanager