Question

当用户滚动屏幕时，我想显示并隐藏Android ActionBar。我找到了一些例子，例如this问题。但是代码显示在这个问题中，它的答案使得动作隐藏在列表滚动了一些像素之后，我想让这个滚动像Google的收件箱应用程序，即操作栏由布局根据用户拉动向上或向下滚动屏幕，换句话说，我想在用户向下/向上滚动的同时显示/隐藏操作栏。

有人面临这样的问题吗？有些想法？

Answer 1

超级简单：

抛弃了ListView。 ListView已成为过去。请改用RecyclerView。
为其添加RecyclerView.OnScrollListener，以逐个像素滚动。
在您的活动布局上使用Toolbar。所以你可以控制它的位置。
在setTranslationY(val)上致电Toolbar，使用RecyclerView“滚动”它。

与上述课程的文档有几个链接：

Answer 2

我创建了基于@Budius和link

的解决方案

首先添加此类

$http.put(apiBase + 'delete', null, {
    params: {
      id: orderId
    }
  }
);

使用简单，只使用recyclerView的addOnScrollListener

添加

public class HidingRecyclerViewScrollListener extends RecyclerView.OnScrollListener {

    private final int UP = 0;
    private final int DOWN = 1;
    private final int margin = 5;
    private View mView;
    RecyclerView.LayoutManager mLayoutManager;

    private float currentPoint = 0;
    private int lastDirection = 1;

    public HidingRecyclerViewScrollListener(View view, LinearLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
        mView = view;
    }

    public HidingRecyclerViewScrollListener(View view, GridLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
        mView = view;
    }

    public HidingRecyclerViewScrollListener(View view, StaggeredGridLayoutManager layoutManager) {
        this.mLayoutManager = layoutManager;
        mView = view;
    }

    public int getFirstVisibleItem(int[] firstVisibleItemPositions) {
        int minSize = 0;
        for (int i = 0; i < firstVisibleItemPositions.length; i++) {
            if (i == 0) {
                minSize = firstVisibleItemPositions[i];
            } else if (firstVisibleItemPositions[i] < minSize) {
                minSize = firstVisibleItemPositions[i];
            }
        }
        return minSize;
    }


    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        float nextPoint = currentPoint + dy;


        if (nextPoint < 0) {
            nextPoint = 0;
        }


        if (nextPoint > viewSize()) {
            nextPoint = viewSize();
        }

        lastDirection = nextPoint >= currentPoint ? UP : DOWN;

        currentPoint = nextPoint;

        mView.setTranslationY(-currentPoint);
    }

    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
        if (newState == RecyclerView.SCROLL_STATE_IDLE) {
            if (lastDirection == UP) {
                if (getFirstVisibleItem() > 0) {

                    currentPoint = viewSize();
                }
            }
            if (lastDirection == DOWN) {
                //Volta para origem
                currentPoint = 0;
            }
            mView.animate().translationY(-currentPoint);
        }
    }

    private int getFirstVisibleItem() {
        int firstVisibleItem = 0;
        if (mLayoutManager instanceof StaggeredGridLayoutManager) {
            int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findFirstVisibleItemPositions(null);
            firstVisibleItem = getFirstVisibleItem(lastVisibleItemPositions);
        } else if (mLayoutManager instanceof LinearLayoutManager) {
            firstVisibleItem = ((LinearLayoutManager) mLayoutManager).findFirstVisibleItemPosition();
        } else if (mLayoutManager instanceof GridLayoutManager) {
            firstVisibleItem = ((GridLayoutManager) mLayoutManager).findFirstVisibleItemPosition();
        }
        return firstVisibleItem;
    }

    private int viewSize() {
        return mView.getHeight() + margin;
    }
}

mView是您要控制的视图
您可以使用LinearLayoutManager，GridLayoutManager和StaggeredGridLayoutManager来使用此类（但我从未使用GridLayoutManager进行测试）

在RecyclerView中使用下面的代码列表不会停留在你想要控制的对象之下，这个代码更简单，更好地测试，但在RecyclerView中使用Hearder就像在上面的链接中说的那样有更好的结果。

recyclerView = (RecyclerView) view.findViewById(R.id.mRecyclerView );
layoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(layoutManager);
recyclerView.addOnScrollListener(new HidingRecyclerViewScrollListener(mView, layoutManager));

如果您使用SwipeRefreshLayout，请使用以下代码显示ProgressBar

android:clipToPadding="false"
android:paddingTop="@dimen/outher_view_dimem"

如何在Google Inbox应用中隐藏和显示Android ActionBar？

2 个答案: