BottomSheet 中的 ListView

Question

我运行遇到一个问题，我在 BottomSheet 中有一个简单的 ListView 并且 ListView 有足够的项目来填满屏幕并滚动更多。

当我向下滚动时，一切似乎都正常，但是当我尝试向上滚动时，它正在滚动 BottomSheet 本身并关闭视图，而不是仅仅滚动 ListView。

一段时间后我找到了解决方案，因为我在这里找不到它，所以我想我会 post 在这里。

Answer 1

解决方案是像这样扩展 ListView：

public class BottomSheetListView extends ListView {
    public BottomSheetListView (Context context, AttributeSet p_attrs) {
        super (context, p_attrs);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return true;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        if (canScrollVertically(this)) {
            getParent().requestDisallowInterceptTouchEvent(true);
        }
        return super.onTouchEvent(ev);
    }

    public boolean canScrollVertically (AbsListView view) {
        boolean canScroll = false;

        if (view !=null && view.getChildCount ()> 0) {
            boolean isOnTop = view.getFirstVisiblePosition() != 0 || view.getChildAt(0).getTop() != 0;
            boolean isAllItemsVisible = isOnTop && view.getLastVisiblePosition() == view.getChildCount();

            if (isOnTop || isAllItemsVisible) {
                canScroll = true;
            }
        }

        return  canScroll;
    }
}

然后在你的布局文件中bottom_sheet_view.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.mypackage.name.BottomSheetListView
        android:id="@+id/listViewBtmSheet"
        android:divider="@color/colorPrimary"
        android:dividerHeight="1dp"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="0dp" />

</LinearLayout>

最后，在你的 Activity/Fragment:

BottomSheetDialog dialog = new BottomSheetDialog(context);
dialog.setContentView(R.layout.bottom_sheet_view);

BottomSheetListView listView = (BottomSheetListView) dialog.findViewById(R.id.listViewBtmSheet);
// apply some adapter - add some data to listview

dialog.show();

这将提供与 ListView 滚动完全兼容的 BottomSheet。

Answer 2

public class BottomSheetListView extends ListView {

    public BottomSheetListView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent motionEvent) {
        View view = (View) getChildAt(getChildCount() - 1);

        int diffBottom = (view.getBottom() - (getHeight() + getScrollY()));
        if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
            if (diffBottom == 0) {
                return false;
            }
        }

         /*//Need more improvement on this logic. Do not uncomment
        int diffTop = (view.getTop() - (getHeight() + getScrollY()));
        if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
            if (diffTop < 0) {
                return true;
            }
        }*/

        return super.onInterceptTouchEvent(motionEvent);
    }

    @Override
    public boolean onTouchEvent(MotionEvent motionEvent) {
        if (canScrollVertically(this)) {
            getParent().requestDisallowInterceptTouchEvent(true);
        }
        return super.onTouchEvent(motionEvent);
    }

    public boolean canScrollVertically(AbsListView absListView) {

        boolean canScroll = false;

        if (absListView != null && absListView.getChildCount() > 0) {

            boolean isOnTop = absListView.getFirstVisiblePosition() != 0 || absListView.getChildAt(0).getTop() != 0;
            boolean isAllItemsVisible = isOnTop && getLastVisiblePosition() == absListView.getChildCount();

            if (isOnTop || isAllItemsVisible)
                canScroll = true;
        }

        return canScroll;
    }
}

Answer 3

如果你不想扩展 ListView:

//in onCreate

_listView.setOnTouchListener(new ListView.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                switch (action) {
                    case MotionEvent.ACTION_DOWN:
                        // Disallow NestedScrollView to intercept touch events.
                        v.getParent().requestDisallowInterceptTouchEvent(true);
                        break;

                    case MotionEvent.ACTION_UP:
                        // Allow NestedScrollView to intercept touch events.
                        v.getParent().requestDisallowInterceptTouchEvent(false);
                        break;
                }

                // Handle ListView touch events.
                v.onTouchEvent(event);
                return true;
            }
        });

Answer 4

我知道这有点乱七八糟，但它对我有用，甚至列表视图都是可选的。正如我们所知，当 bottom sheet 改变它的状态时，它可以被它的监听器捕获，所以如果 listview 没有触及顶部，不要让它改变状态，此后 touch 事件将被传递给 listview 并将作为确实如此。

    mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback(){
@Override
public void onStateChanged(View bottomSheet, int newState) {
        if (newState == BottomSheetBehavior.STATE_DRAGGING && !listIsAtTop()){
            mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
        }
}
@Override
public void onSlide(View bottomSheet, float slideOffset) {}});

public boolean listIsAtTop()   {
    if(tripListView.getChildCount() == 0) return true;
    return (tripListView.getChildAt(0).getTop() == 0 && tripListView.getFirstVisiblePosition() ==0);
}

Answer 5

这是带有触摸事件处理的正确列表视图自定义 class

public class BottomSheetListView extends ListView
{
    public BottomSheetListView(Context context, AttributeSet p_attrs)
    {
        super(context, p_attrs);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev)
    {
        if (canScrollVertically(this))
        {
            getParent().requestDisallowInterceptTouchEvent(true);
        }
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev)
    {
        if (canScrollVertically(this))
        {
            getParent().requestDisallowInterceptTouchEvent(true);
        }
        return super.onTouchEvent(ev);
    }

    public boolean canScrollVertically(AbsListView view)
    {
        boolean canScroll = false;

        if (view != null && view.getChildCount() > 0)
        {
            boolean isOnTop = view.getFirstVisiblePosition() != 0 || view.getChildAt(0).getTop() != 0;
            boolean isAllItemsVisible = isOnTop && view.getLastVisiblePosition() == view.getChildCount();

            if (isOnTop || isAllItemsVisible)
            {
                canScroll = true;
            }
        }

        return canScroll;
    }
}

Answer 6

从 版本 22.1.0 开始，您可能想尝试 setNestedScrollingEnabled=true

If this property is set to true the view will be permitted to initiate nested scrolling operations with a compatible parent view in the current hierarchy. If this view does not implement nested scrolling this will have no effect. Disabling nested scrolling while a nested scroll is in progress has the effect of stopping the nested scroll.

Reference to Google API

Answer 7

我已经尝试过此处描述的嵌套 ListView，但它们不允许在触摸 ListView 时展开/折叠底部 sheet。下面是我的解决方案，当你向上滚动而ListView无法向上滚动时，底部sheet将展开，当你向下滚动且ListView无法向上滚动时，BottomSheet将被展开崩溃了。

public class NestedListView extends ListView {

    private boolean mIsBeingDragged = false;
    private float mLastMotionY;

    public NestedListView(final Context context, final AttributeSet attrs) {
        super(context, attrs);
    }

    public NestedListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        switch (event.getActionMasked()) {
            case MotionEvent.ACTION_DOWN: {
                if (canScrollDown() || canScrollUp()) {
                    final ViewParent parent = getParent();
                    if (parent != null) {
                        parent.requestDisallowInterceptTouchEvent(true);
                    }
                }
                break;
            }
        }
        return super.onInterceptTouchEvent(event);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        final float y = event.getRawY();

        switch (event.getActionMasked()) {
            case MotionEvent.ACTION_MOVE: {
                if (!mIsBeingDragged) {
                    final float deltaY = mLastMotionY - y;
                    mIsBeingDragged = (deltaY > 0 && canScrollDown())
                        || (deltaY < 0 && canScrollUp());

                    if (mIsBeingDragged) {
                        final ViewParent parent = getParent();
                        if (parent != null) {
                            parent.requestDisallowInterceptTouchEvent(true);
                        }
                    } else {
                        final ViewParent parent = getParent();
                        if (parent != null) {
                            parent.requestDisallowInterceptTouchEvent(false);
                        }
                        return false;
                    }
                }
            }

            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                mIsBeingDragged = false;
                break;
        }

        mLastMotionY = y;

        return super.onTouchEvent(event);
    }

    public boolean canScrollUp() {
        final int childCount = getChildCount();
        if (childCount == 0) {
            return false;
        }

        final int firstPosition = getFirstVisiblePosition();
        final int firstTop = getChildAt(0).getTop();
        return firstPosition > 0 || firstTop < getListPaddingTop();
    }

    public boolean canScrollDown() {
        final int childCount = getChildCount();
        if (childCount == 0) {
            return false;
        }

        final int firstPosition = getFirstVisiblePosition();
        final int lastBottom = getChildAt(childCount - 1).getBottom();
        final int lastPosition = firstPosition + childCount;
        return lastPosition < getCount() || lastBottom > getHeight() - getListPaddingBottom();
    }
}

Answer 8

只需将 android:nestedScrollingEnabled 设置为 true 布局为 ListView 属性或 listView.setNestedScrollingEnabled(true) 在 java.

BottomSheet 中的 ListView

ListView in BottomSheet

android

listview

bottom-sheet