android在拖放的同时滚动

| 嗨，我正在尝试在ListView上进行拖放。效果很好。但是我失去了单击和滚动的能力。如何保留这两个？我认为拖放应该在长按该项目而不是正常按下时进行。这是位于扩展ListView的MyListView中的onTouch

@Override
    public boolean onTouchEvent(MotionEvent ev) {
        final int action = ev.getAction();
        final int x = (int) ev.getX();
        final int y = (int) ev.getY();  

        if (action == MotionEvent.ACTION_DOWN && x < this.getWidth()/4) {
            this._dragMode = true;
        }

        if (!this._isDragNDrop) 
            return super.onTouchEvent(ev);

        switch (action) {
            case MotionEvent.ACTION_DOWN:
                this._startPosition = pointToPosition(x,y);
                if (this._startPosition != INVALID_POSITION) {
                    int mItemPosition = this._startPosition - getFirstVisiblePosition();
                    this._dragPointOffset = y - getChildAt(mItemPosition).getTop();
                    this._dragPointOffset -= ((int)ev.getRawY()) - y;
                    startDrag(mItemPosition,y);
                    drag(x,y);
                }   
                break;
            case MotionEvent.ACTION_MOVE:
                drag(x,y);
                break;
            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
            default:
                this._dragMode = false;
                //_isDragNDrop = false;
                this._endPosition = pointToPosition(x,y);
                stopDrag(this._startPosition - getFirstVisiblePosition());
                if (this._dropListener != null && this._startPosition != INVALID_POSITION && this._endPosition != INVALID_POSITION) 
                    this._dropListener.onDrop(this._startPosition, this._endPosition);
                break;
        }
        return true;
    }

已邀请:

5 个回复

揽芳僵迷仇

我刚刚在我的应用程序中实现了拖放列表视图，长按一个项目即可开始拖动。源代码在GitHub上：DraggableListView，我有一篇博客文章对此进行了描述。希望对您有帮助。

厢界山攀

我正在实施类似的东西。希望这将对其他人有所帮助，因为我仍在解决问题。

...
thumb.setOnDragListener(new Drag());
...

public class Drag implements OnDragListener{
public static int PositionOfDraggedItem = -1;
      public int PositionOfItemDraggedOver = -1;

public Drag() {}

@Override
public boolean onDrag(View v, DragEvent event)
{
    final int action = event.getAction();
    boolean state = true;

    View root = v.getRootView();
    ListView List = (ListView) root.findViewById(android.R.id.list);
    Object holder = v.getTag() instanceof OrderHolder? (OrderHolder)v.getTag() : v.getTag();

    String BookId = holder instanceof OrderHolder? String.valueOf(((OrderHolder)holder).id) : (String)holder;

    switch(action)
    {
        case DragEvent.ACTION_DRAG_STARTED:

            break;
        case DragEvent.ACTION_DRAG_ENTERED:
            if( PositionOfDraggedItem != -1 )
            {
                if( this.PositionOfItemDraggedOver != PositionOfDraggedItem )
                {
                    if( v.getBackground() != null )
                        v.setBackgroundDrawable(v.getContext().getResources().getDrawable(drawable.row_ovr));
                }
            }
            break;
        case DragEvent.ACTION_DRAG_LOCATION:
            /**
             * Set the item being
             * here, as it will not
             * provide location data
             * anywhere else
             */
            if( PositionOfDraggedItem == -1 )
                PositionOfDraggedItem = List.getPositionForView(v);

            /**
             * Set the view thats
             * being dragged over
             */
            this.PositionOfItemDraggedOver = List.getPositionForView(v);

            int PositionOfLastVisibleView = List.getLastVisiblePosition();
            int PositionOfFirstVisibleView = List.getFirstVisiblePosition();

            if( this.PositionOfItemDraggedOver != -1 && ( this.PositionOfItemDraggedOver != PositionOfDraggedItem ) ){
                if( this.PositionOfItemDraggedOver == PositionOfLastVisibleView-1 || this.PositionOfItemDraggedOver == PositionOfLastVisibleView || this.PositionOfItemDraggedOver == PositionOfLastVisibleView+1 ){
                    List.smoothScrollToPosition(PositionOfLastVisibleView+1);
                }else if( this.PositionOfItemDraggedOver == PositionOfFirstVisibleView-1 || this.PositionOfItemDraggedOver == PositionOfFirstVisibleView+1 || this.PositionOfItemDraggedOver == PositionOfFirstVisibleView ){
                    List.smoothScrollToPosition(PositionOfFirstVisibleView-1);
                }
            }
            break;
        case DragEvent.ACTION_DRAG_EXITED:
            if( v.getBackground() != null )
                v.setBackgroundDrawable(v.getContext().getResources().getDrawable(drawable.row));
            break;
        case DragEvent.ACTION_DROP:
            if(event != null)
            {
                ClipData data = event.getClipData();
                if( data != null && data.getItemCount() > 0 )
                {
                    if( !data.getItemAt(0).getText().toString().equalsIgnoreCase(BookId) )
                    {
                        if( v.getBackground() != null )
                            v.setBackgroundDrawable(v.getContext().getResources().getDrawable(drawable.row));
                        /**
                         * Ordering info for
                         * book being dragged
                         */
                        String oShelfOrder = BookManager.item(v.getContext().getContentResolver(), dbhelper.BOOKS_SHELFORDER, 
                                booksprovider.GetUri(dbhelper.BOOKS), Long.parseLong(data.getItemAt(0).getText().toString()));
                        String oBookOrder = BookManager.item(v.getContext().getContentResolver(), dbhelper.BOOKS_BOOKSORDER, 
                                booksprovider.GetUri(dbhelper.BOOKS), Long.parseLong(data.getItemAt(0).getText().toString()));

                        /**
                         * Ordering info
                         * for book being dragged
                         * to
                         */
                        String dShelfOrder = BookManager.item(v.getContext().getContentResolver(), dbhelper.BOOKS_SHELFORDER, 
                                booksprovider.GetUri(dbhelper.BOOKS), Long.parseLong(BookId));
                        String dBookOrder = BookManager.item(v.getContext().getContentResolver(), dbhelper.BOOKS_BOOKSORDER, 
                                booksprovider.GetUri(dbhelper.BOOKS), Long.parseLong(BookId));

                        /**
                         * Update book being dragged
                         */
                        ContentValues args = new ContentValues();
                        args.put(dbhelper.BOOKS_SHELFORDER, dShelfOrder);
                        args.put(dbhelper.BOOKS_BOOKSORDER, dBookOrder);
                        BookManager.updateBook(v.getContext().getContentResolver(), data.getItemAt(0).getText().toString(), args);

                        /**
                         * Update book being dragged to
                         */
                        ContentValues values = new ContentValues();
                        values.put(dbhelper.BOOKS_SHELFORDER, oShelfOrder);
                        values.put(dbhelper.BOOKS_BOOKSORDER, oBookOrder);
                        BookManager.updateBook(v.getContext().getContentResolver(), BookId, values);

                        if( v.getContext() instanceof OrderBooks ){
                            ((OrderBooks)v.getContext()).adapter.refresh();
                            ((OrderBooks)v.getContext()).adapter.notifyDataSetChanged();

                            PositionOfDraggedItem = -1;
                        }
                    }
                }
            }
            break;
        case DragEvent.ACTION_DRAG_ENDED:
            if( event != null && event.getResult())
            {
                v.invalidate();
            }
            break;
    }
    return state;
}

} 一段时间未进行任何处理，已更新以反映最新更改。

混侩闯空坷

请查看此问题以获取其他帮助。我还有一个名为DragSortListView的组件，我花了很长时间来完善它。你可以在这里找到它： https://github.com/bauerca/drag-sort-listview 我可以帮助您将长按启动的拖动整合到上述仓库中。

担每棱绰

我实施了对我有用的解决方案。以下方法位于我的Activity中，当dragEvent为ACTION_DRAG_ENTERED时，将在我的dragEventListener中调用以下方法。我声明了一些属性：

//first visible item (getFirstVisiblePosition() does not work for me)
int firstVisible;
//number of scrolls
int nbrScroll;
//my listview to scroll
ListView mListView;
//the adapter of my listview
SimpleAdapter mAdapter;

...

public void scrollDrag(int position) {
            //this is the position of the item in my listview
            //to scroll down
            //test if the item entered is the last visible
    if (position == mListView.getLastVisiblePosition()
            && id < mListView.getCount()) {
        mAdapter.notifyDataSetChanged();
        mRightDrawerList.post(new Runnable() {
            @Override
            public void run() {
                //scroll down
                mListView.smoothScrollToPosition(mListView
                        .getLastVisiblePosition() + 1);
                firstVisible++;
            }
        });
            //to scroll up
            //test if the item entered is the first visible
    } else if (position == firstVisible && position !=0) {
        mAdapter.notifyDataSetChanged();
        mListView.post(new Runnable() {
            @Override
            public void run() {
                //scroll up
                mListView.smoothScrollToPosition(firstVisible-1);
                firstVisible --;
            }
        });
    }
}

希望它会帮助某人。

翁茄口霉氖

伙计们，我对rickey的代码进行了一些更改，这对我来说很有效。

if (PositionOfItemDraggedOver == PositionOfLastVisibleView)
    order_item_list_lv.smoothScrollToPosition(PositionOfLastVisibleView + 1);

if (PositionOfItemDraggedOver == PositionOfFirstVisibleView)
   order_item_list_lv.smoothScrollToPosition(PositionOfFirstVisibleView - 1);

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android在拖放的同时滚动

5 个回复

发起人

listview

drag_and_drop

android

问题状态

android在拖放的同时滚动

与内容相关的链接

5 个回复

发起人

listview

drag_and_drop

android

问题状态