android.support.v7.widget.LinearLayoutManager#findLastVisibleItemPosition ( )源码实例Demo

下面列出了android.support.v7.widget.LinearLayoutManager#findLastVisibleItemPosition ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。

源代码1 项目： WanAndroid 文件： LMRecyclerView.java

/**
 * 滑动监听
 * @param recyclerView
 * @param dx
 * @param dy
 */
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    LayoutManager layoutManager = recyclerView.getLayoutManager();

    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayout = (LinearLayoutManager) layoutManager;
        int mLastChildPosition = linearLayout.findLastVisibleItemPosition();
        int itemTotalCount = linearLayout.getItemCount();
        View lastChildView = linearLayout.getChildAt(linearLayout.getChildCount() - 1);
        int lastChildBottom = lastChildView.getBottom();
        int recyclerBottom = getBottom();
        if (mLastChildPosition == itemTotalCount - 1 && lastChildBottom == recyclerBottom) {
            if (isCanLoadMore && listener != null) {
                //业务代码
                listener.loadMore();
            }
        }
    }
}

源代码2 项目： MaoWanAndoidClient 文件： NavigationFragment.java

private void moveToPosition(LinearLayoutManager layoutManager, RecyclerView recyclerView, int position) {
    // 第一个可见的view的位置
    int firstItem = layoutManager.findFirstVisibleItemPosition();
    // 最后一个可见的view的位置
    int lastItem = layoutManager.findLastVisibleItemPosition();
    if (position <= firstItem) {
        // 如果跳转位置firstItem 之前(滑出屏幕的情况)，就smoothScrollToPosition可以直接跳转，
        recyclerView.smoothScrollToPosition(position);
    } else if (position <= lastItem) {
        // 跳转位置在firstItem 之后，lastItem 之间（显示在当前屏幕），smoothScrollBy来滑动到指定位置
        int top = recyclerView.getChildAt(position - firstItem).getTop();
        recyclerView.smoothScrollBy(0, top);
    } else {
        // 如果要跳转的位置在lastItem 之后，则先调用smoothScrollToPosition将要跳转的位置滚动到可见位置
        // 再通过onScrollStateChanged控制再次调用当前moveToPosition方法，执行上一个判断中的方法
        recyclerView.smoothScrollToPosition(position);
        scrollToPosition = position;
        canScroll = true;
    }
}

源代码3 项目： AndroidDemo 文件： RecyclerViewScrollActivity.java

private void moveToPosition(int position) {
    if (position > data.size())
        return;
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    int first = layoutManager.findFirstVisibleItemPosition();
    int end = layoutManager.findLastVisibleItemPosition();
    if (first == -1 || end == -1)
        return;
    if (position <= first) {
        layoutManager.scrollToPosition(position);
    } else if (position >= end) {
        isMove = true;
        scrollPosition = position;
        layoutManager.smoothScrollToPosition(recyclerView, null, position);
    } else {//中间部分
        int n = position - layoutManager.findFirstVisibleItemPosition();
        if (n > 0 && n < data.size()) {
            int top = layoutManager.findViewByPosition(position).getTop();
            recyclerView.scrollBy(0, top);
        }
    }
}

源代码4 项目： Synapse 文件： MainActivity.java

@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
    if (newState != RecyclerView.SCROLL_STATE_IDLE
            || !(recyclerView.getLayoutManager() instanceof LinearLayoutManager)
            || recyclerView.getChildCount() < AVAILABLE) {
        return;
    }

    final LinearLayoutManager manager = (LinearLayoutManager) recyclerView.getLayoutManager();

    final int totalItemCount = recyclerView.getAdapter().getItemCount();
    final int lastVisibleItemPosition = manager.findLastVisibleItemPosition();

    if (lastVisibleItemPosition == totalItemCount - 1) {
        mTrack.logEvent(TrackCons.Main.SCROLL_BOTTOM);
    }
}

源代码5 项目： SnappyRecyclerView 文件： SnappingRecyclerView.java

/**
 * Calculates the distance between the RecyclerView's anchor, either the start, center or end,
 * and the View which is closest to the anchor.
 *
 * @return The distance between RecyclerView anchor and View closest to anchor
 */
private int calculateSnapDistance() {
    LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getLayoutManager();

    int parentAnchor = getParentAnchor(orientation, anchor);

    int lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition();
    int firstVisibleItemPosition = linearLayoutManager.findFirstVisibleItemPosition();

    View currentViewClosestToAnchor = linearLayoutManager.findViewByPosition(firstVisibleItemPosition);

    int currentViewClosestToAnchorDistance = parentAnchor - getViewAnchor(currentViewClosestToAnchor, orientation, anchor);

    for(int i = firstVisibleItemPosition + 1; i <= lastVisibleItemPosition; i++) {
        View view = linearLayoutManager.findViewByPosition(i);
        int distanceToAnchor = parentAnchor - getViewAnchor(view, orientation, anchor);

        if (Math.abs(distanceToAnchor) < Math.abs(currentViewClosestToAnchorDistance)) {
            currentViewClosestToAnchorDistance = distanceToAnchor;
        }
    }

    return currentViewClosestToAnchorDistance;
}

源代码6 项目： espresso-macchiato 文件： LayoutManagerItemVisibilityAssertion.java

@Override
public void check(View view, NoMatchingViewException noViewFoundException) {
    if (noViewFoundException != null) {
        throw noViewFoundException;
    }

    RecyclerView recyclerView = (RecyclerView) view;
    if (recyclerView.getLayoutManager() instanceof LinearLayoutManager) {
        LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
        int firstVisibleItem = layoutManager.findFirstVisibleItemPosition();
        int lastVisibleItem = layoutManager.findLastVisibleItemPosition();

        boolean indexInRange = firstVisibleItem <= index && index <= lastVisibleItem;
        if ((shouldBeVisible && !indexInRange) || (!shouldBeVisible && indexInRange)) {
            String errorMessage = "expected item " + index + " to " +
                    (shouldBeVisible ? "" : "not") + " be visible, but was" +
                    (indexInRange ? "" : " not") + " visible";
            throw new AssertionError(errorMessage);

        }
    }
}

源代码7 项目： BaseQuickAdapter 文件： EndlessScrollListener.java

@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {

    BaseQuickAdapter adapter = (BaseQuickAdapter) recyclerView.getAdapter();

    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    int lastVisibleItemPosition = layoutManager.findLastVisibleItemPosition();
    if (newState == RecyclerView.SCROLL_STATE_IDLE && lastVisibleItemPosition + 1 == layoutManager.getItemCount() && adapter.isHasMore()) {
        //当已经滑到最后一条的时候
        adapter.isLoadingMore();
    }
}

源代码8 项目： CustomViewSets 文件： SnappyRecyclerView.java

@Override
    public void onScrollStateChanged(int state) {
        super.onScrollStateChanged(state);

        // If you tap on the phone while the RecyclerView is scrolling it will stop in the middle.
        // This code fixes this. This code is not strictly necessary but it improves the behaviour.

        if (state == SCROLL_STATE_IDLE) {
            LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getLayoutManager();

//            int screenWidth = Resources.getSystem().getDisplayMetrics().widthPixels;
            int screenWidth = getMeasuredWidth();
            // views on the screen
            int lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition();
            View lastView = linearLayoutManager.findViewByPosition(lastVisibleItemPosition);
            int firstVisibleItemPosition = linearLayoutManager.findFirstVisibleItemPosition();
            View firstView = linearLayoutManager.findViewByPosition(firstVisibleItemPosition);

            // distance we need to scroll
            int leftMargin = (screenWidth - lastView.getWidth()) / 2;
            int rightMargin = (screenWidth - firstView.getWidth()) / 2 + firstView.getWidth();
            int leftEdge = lastView.getLeft();
            int rightEdge = firstView.getRight();
            int scrollDistanceLeft = leftEdge - leftMargin;
            int scrollDistanceRight = rightMargin - rightEdge;

            if (leftEdge > screenWidth / 2) {
                smoothScrollBy(-scrollDistanceRight, 0);
            } else if (rightEdge < screenWidth / 2) {
                smoothScrollBy(scrollDistanceLeft, 0);
            }
        }
    }

源代码9 项目： Expandable-RecyclerView 文件： ExpandableRecyclerView.java

@Override
public void run() {
	if (getLayoutManager() instanceof LinearLayoutManager && isFirstLayoutPassed() && getExpandableAdapter()!=null) {
		LinearLayoutManager layoutManager = (LinearLayoutManager) getLayoutManager();
		int first = layoutManager.findFirstVisibleItemPosition();
		int last = layoutManager.findLastVisibleItemPosition();
		getAdapter().notifyItemRangeChanged(first, last);
	}
}

源代码10 项目： SteamGifts 文件： EndlessAdapter.java

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    if (layoutManager == null)
        throw new IllegalStateException("Can't handle scrolling without a LayoutManager");

    int lastVisibleItem = layoutManager.findLastVisibleItemPosition();

    if (!loading && layoutManager.getItemCount() <= (lastVisibleItem + 5)) {
        startLoading();
    }
}

源代码11 项目： OpenHub 文件： ListFragment.java

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    if(!loadMoreEnable || !canLoadMore || isLoading ||
            !NetHelper.INSTANCE.getNetEnabled()) return;
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    //only LinearLayoutManager can find last visible
    if(layoutManager instanceof LinearLayoutManager){
        LinearLayoutManager linearManager = (LinearLayoutManager) layoutManager;
        int lastPosition = linearManager.findLastVisibleItemPosition();
        if(lastPosition == adapter.getItemCount() - 1){
            onLoadMore(++curPage);
        }
    }
}

源代码12 项目： Gank-Veaer 文件： GankListActivity.java

RecyclerView.OnScrollListener getScrollToBottomListener(final LinearLayoutManager linearLayoutManager) {
    return new RecyclerView.OnScrollListener() {
        @Override public void onScrolled(RecyclerView rv, int dx, int dy) {
            boolean isBottom = linearLayoutManager.findLastVisibleItemPosition() == (feedsList.size() - 1);
            if (!refreshLayout.isRefreshing() && isBottom) {
                refreshLayout.setRefreshing(true);
                nextPage++;
                initGankData(nextPage, false);
            }
        }
    };
}

源代码13 项目： Android-MVVMFramework 文件： BaseRecyclerViewModel.java

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    int lastVisibleItem = layoutManager.findLastVisibleItemPosition();
    int totalItemCount = layoutManager.getItemCount();
    //lastVisibleItem >= totalItemCount - 1 表示剩下1个item自动加载
    // dy>0 表示向下滑动
    if (lastVisibleItem >= totalItemCount - 1 && dy > 0) {
        onListLoadMore();
    }
}

源代码14 项目： YCScrollPager 文件： ScrollPageHelper.java

@Nullable
private View findStartView(RecyclerView.LayoutManager layoutManager,
                           @NonNull OrientationHelper helper) {

    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        boolean reverseLayout = linearLayoutManager.getReverseLayout();
        int firstChild = reverseLayout ? linearLayoutManager.findLastVisibleItemPosition()
                : linearLayoutManager.findFirstVisibleItemPosition();
        int offset = 1;

        if (layoutManager instanceof GridLayoutManager) {
            offset += ((GridLayoutManager) layoutManager).getSpanCount() - 1;
        }

        if (firstChild == RecyclerView.NO_POSITION) {
            return null;
        }

        View child = layoutManager.findViewByPosition(firstChild);

        float visibleWidth;
        if (isRtlHorizontal) {
            visibleWidth = (float) (helper.getTotalSpace() - helper.getDecoratedStart(child))
                    / helper.getDecoratedMeasurement(child);
        } else {
            visibleWidth = (float) helper.getDecoratedEnd(child)
                    / helper.getDecoratedMeasurement(child);
        }
        boolean endOfList;
        if (!reverseLayout) {
            endOfList = ((LinearLayoutManager) layoutManager)
                    .findLastCompletelyVisibleItemPosition()
                    == layoutManager.getItemCount() - 1;
        } else {
            endOfList = ((LinearLayoutManager) layoutManager)
                    .findFirstCompletelyVisibleItemPosition()
                    == 0;
        }

        if (visibleWidth > 0.5f && !endOfList) {
            return child;
        } else if (snapLastItem && endOfList) {
            return child;
        } else if (endOfList) {
            return null;
        } else {
            return reverseLayout ? layoutManager.findViewByPosition(firstChild - offset)
                    : layoutManager.findViewByPosition(firstChild + offset);
        }
    }

    return null;
}

源代码15 项目： YCScrollPager 文件： ScrollPageHelper.java

@Nullable
private View findEndView(RecyclerView.LayoutManager layoutManager,
                         @NonNull OrientationHelper helper) {

    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        boolean reverseLayout = linearLayoutManager.getReverseLayout();
        int lastChild = reverseLayout ? linearLayoutManager.findFirstVisibleItemPosition()
                : linearLayoutManager.findLastVisibleItemPosition();
        int offset = 1;

        if (layoutManager instanceof GridLayoutManager) {
            offset += ((GridLayoutManager) layoutManager).getSpanCount() - 1;
        }

        if (lastChild == RecyclerView.NO_POSITION) {
            return null;
        }

        View child = layoutManager.findViewByPosition(lastChild);

        float visibleWidth;

        if (isRtlHorizontal) {
            visibleWidth = (float) helper.getDecoratedEnd(child)
                    / helper.getDecoratedMeasurement(child);
        } else {
            visibleWidth = (float) (helper.getTotalSpace() - helper.getDecoratedStart(child))
                    / helper.getDecoratedMeasurement(child);
        }

        boolean startOfList;
        if (!reverseLayout) {
            startOfList = ((LinearLayoutManager) layoutManager)
                    .findFirstCompletelyVisibleItemPosition() == 0;
        } else {
            startOfList = ((LinearLayoutManager) layoutManager)
                    .findLastCompletelyVisibleItemPosition()
                    == layoutManager.getItemCount() - 1;
        }

        if (visibleWidth > 0.5f && !startOfList) {
            return child;
        } else if (snapLastItem && startOfList) {
            return child;
        } else if (startOfList) {
            return null;
        } else {
            return reverseLayout ? layoutManager.findViewByPosition(lastChild + offset)
                    : layoutManager.findViewByPosition(lastChild - offset);
        }
    }
    return null;
}

源代码16 项目： AndroidPlusJava 文件： BaseRefreshableListFragment.java

private boolean shouldLoadMore() {
    LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
    return layoutManager.findLastVisibleItemPosition() == mRecyclerView.getAdapter().getItemCount() - 1;
}

源代码17 项目： CustomViewSets 文件： SnappyRecyclerView.java

@Override
    public boolean fling(int velocityX, int velocityY) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getLayoutManager();

//        int screenWidth = Resources.getSystem().getDisplayMetrics().widthPixels;
        int screenWidth = getMeasuredWidth();
        // views on the screen
        int lastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition();
        View lastView = linearLayoutManager.findViewByPosition(lastVisibleItemPosition);
        int firstVisibleItemPosition = linearLayoutManager.findFirstVisibleItemPosition();
        View firstView = linearLayoutManager.findViewByPosition(firstVisibleItemPosition);

        // distance we need to scroll
        int leftMargin = (screenWidth - lastView.getWidth()) / 2;
        int rightMargin = (screenWidth - firstView.getWidth()) / 2 + firstView.getWidth();
        int leftEdge = lastView.getLeft();
        int rightEdge = firstView.getRight();
        int scrollDistanceLeft = leftEdge - leftMargin;
        int scrollDistanceRight = rightMargin - rightEdge;

        if (Math.abs(velocityX) < 1000) {
            // The fling is slow -> stay at the current page if we are less than half through,
            // or go to the next page if more than half through

            if (leftEdge > screenWidth / 2) {
                // go to next page
                smoothScrollBy(-scrollDistanceRight, 0);
            } else if (rightEdge < screenWidth / 2) {
                // go to next page
                smoothScrollBy(scrollDistanceLeft, 0);
            } else {
                // stay at current page
                if (velocityX > 0) {
                    smoothScrollBy(-scrollDistanceRight, 0);
                } else {
                    smoothScrollBy(scrollDistanceLeft, 0);
                }
            }
            return true;

        } else {
            // The fling is fast -> go to next page

            if (velocityX > 0) {
                smoothScrollBy(scrollDistanceLeft, 0);
            } else {
                smoothScrollBy(-scrollDistanceRight, 0);
            }
            return true;

        }

    }

源代码18 项目： YCBanner 文件： ScrollPageHelper.java

@Nullable
private View findStartView(RecyclerView.LayoutManager layoutManager,
                           @NonNull OrientationHelper helper) {

    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        boolean reverseLayout = linearLayoutManager.getReverseLayout();
        int firstChild = reverseLayout ? linearLayoutManager.findLastVisibleItemPosition()
                : linearLayoutManager.findFirstVisibleItemPosition();
        int offset = 1;

        if (layoutManager instanceof GridLayoutManager) {
            offset += ((GridLayoutManager) layoutManager).getSpanCount() - 1;
        }

        if (firstChild == RecyclerView.NO_POSITION) {
            return null;
        }

        View child = layoutManager.findViewByPosition(firstChild);

        float visibleWidth;
        if (isRtlHorizontal) {
            visibleWidth = (float) (helper.getTotalSpace() - helper.getDecoratedStart(child))
                    / helper.getDecoratedMeasurement(child);
        } else {
            visibleWidth = (float) helper.getDecoratedEnd(child)
                    / helper.getDecoratedMeasurement(child);
        }
        boolean endOfList;
        if (!reverseLayout) {
            endOfList = ((LinearLayoutManager) layoutManager)
                    .findLastCompletelyVisibleItemPosition()
                    == layoutManager.getItemCount() - 1;
        } else {
            endOfList = ((LinearLayoutManager) layoutManager)
                    .findFirstCompletelyVisibleItemPosition()
                    == 0;
        }

        if (visibleWidth > 0.5f && !endOfList) {
            return child;
        } else if (snapLastItem && endOfList) {
            return child;
        } else if (endOfList) {
            return null;
        } else {
            return reverseLayout ? layoutManager.findViewByPosition(firstChild - offset)
                    : layoutManager.findViewByPosition(firstChild + offset);
        }
    }

    return null;
}

源代码19 项目： the-tech-frontier-app 文件： AutoLoadRecyclerView.java

private boolean isBottom(int dx, int dy) {
    LinearLayoutManager layoutManager = (LinearLayoutManager) getLayoutManager();
    int lastVisibleItem = layoutManager.findLastVisibleItemPosition();
    int totalItemCount = layoutManager.getItemCount();
    return lastVisibleItem >= totalItemCount - 4 && dy > 0;
}

源代码20 项目： YCRefreshView 文件： ScrollPageHelper.java

@Nullable
private View findEndView(RecyclerView.LayoutManager layoutManager,
                         @NonNull OrientationHelper helper) {

    if (layoutManager instanceof LinearLayoutManager) {
        LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
        boolean reverseLayout = linearLayoutManager.getReverseLayout();
        int lastChild = reverseLayout ? linearLayoutManager.findFirstVisibleItemPosition()
                : linearLayoutManager.findLastVisibleItemPosition();
        int offset = 1;

        if (layoutManager instanceof GridLayoutManager) {
            offset += ((GridLayoutManager) layoutManager).getSpanCount() - 1;
        }

        if (lastChild == RecyclerView.NO_POSITION) {
            return null;
        }

        View child = layoutManager.findViewByPosition(lastChild);

        float visibleWidth;

        if (isRtlHorizontal) {
            visibleWidth = (float) helper.getDecoratedEnd(child)
                    / helper.getDecoratedMeasurement(child);
        } else {
            visibleWidth = (float) (helper.getTotalSpace() - helper.getDecoratedStart(child))
                    / helper.getDecoratedMeasurement(child);
        }

        boolean startOfList;
        if (!reverseLayout) {
            startOfList = ((LinearLayoutManager) layoutManager)
                    .findFirstCompletelyVisibleItemPosition() == 0;
        } else {
            startOfList = ((LinearLayoutManager) layoutManager)
                    .findLastCompletelyVisibleItemPosition()
                    == layoutManager.getItemCount() - 1;
        }

        if (visibleWidth > 0.5f && !startOfList) {
            return child;
        } else if (snapLastItem && startOfList) {
            return child;
        } else if (startOfList) {
            return null;
        } else {
            return reverseLayout ? layoutManager.findViewByPosition(lastChild + offset)
                    : layoutManager.findViewByPosition(lastChild - offset);
        }
    }
    return null;
}

方法所在类

android.support.v7.widget.LinearLayoutManager