改变使用拖放功能

Question

我想用拖动改变文本视图的位置，并使用拖放监听器和动画的Android功能下降两个视点（文字版）的位置。我使用下面的代码完成了一个设计。我想要使​​用Drag Listener更改文本视图的顺序。感谢i give a image of design and i want change position of text view using drag and drop

public void loadtable() 

{ 


    Sorting_Linear = (LinearLayout) findViewById(R.id.Sorting_Linear); 
    submit = (Button) findViewById(R.id.submit); 
    LinearLayout[] llRow = new LinearLayout[5]; 

    final TextView[] outletnametxt = new TextView[5]; 
    final ImageView[] imageButtonup = new ImageView[5]; 
    final ImageView[] imageButtondown = new ImageView[5]; 
    final LinearLayout[] Linearlayout = new LinearLayout[5]; 


    for (int i = 0; i < 5; i++) { 

     llRow[i] = new LinearLayout(mContext); 
     LinearLayout.LayoutParams paramsllRow = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT); 
     paramsllRow.setMargins(0, 2, 0, 0); 
     llRow[i].setLayoutParams(paramsllRow); 
     llRow[i].setOrientation(LinearLayout.HORIZONTAL); 

     outletnametxt[i] = new TextView(mContext); 
     outletnametxt[i].setLayoutParams(nametxt); 
     outletnametxt[i].setText(olm_name[i]); 
     outletnametxt[i].setTextAlignment(View.TEXT_ALIGNMENT_CENTER); 
     outletnametxt[i].setTextSize(20); 
     outletnametxt[i].setGravity(Gravity.CENTER); 
     outletnametxt[i].setBackgroundColor(mContext.getResources().getColor(android.R.color.white)); 
     llRow[i].addView(outletnametxt[i]); 


     imageButtonup[i] = new ImageView(mContext); 
     imageButtonup[i].setLayoutParams(imagebtnup); 
     imageButtonup[i].setImageResource(R.drawable.arrowup); 


     imageButtondown[i] = new ImageView(mContext); 
     imageButtondown[i].setLayoutParams(imagebtndown); 
     imageButtondown[i].setImageResource(R.drawable.arrowdown); 


     Linearlayout[i] = new LinearLayout(mContext); 
     Linearlayout[i].setLayoutParams(linearlayout); 
     Linearlayout[i].setTextAlignment(View.TEXT_ALIGNMENT_CENTER); 
     Linearlayout[i].setBackgroundColor(mContext.getResources().getColor(android.R.color.white)); 
     Linearlayout[i].setOrientation(LinearLayout.VERTICAL); 
     Linearlayout[i].addView(imageButtonup[i]); 
     Linearlayout[i].addView(imageButtondown[i]); 
     llRow[i].addView(Linearlayout[i]); 

     Sorting_Linear.addView(llRow[i]); 


    } 

Answer 1

下面创建接口ItemTouchHelperAdapter

public interface ItemTouchHelperAdapter { 

boolean onItemMove(int fromPosition, int toPosition); 

void onItemDismiss(int position);} 

创建第二接口ItemTouchHelperViewHolder

public interface ItemTouchHelperViewHolder { 

void onItemSelected(); 

void onItemClear();} 

创建OnStartDragListener

public interface OnStartDragListener { 

void onStartDrag(RecyclerView.ViewHolder viewHolder);} 

下面创建类

public class SimpleItemTouchHelperCallback extends ItemTouchHelper.Callback { 

public static final float ALPHA_FULL = 1.0f; 

private final ItemTouchHelperAdapter mAdapter; 

public SimpleItemTouchHelperCallback(ItemTouchHelperAdapter adapter) { 
    mAdapter = adapter; 
} 

@Override 
public boolean isLongPressDragEnabled() { 
    return true; 
} 

@Override 
public boolean isItemViewSwipeEnabled() { 
    return true; 
} 

@Override 
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) { 
    // Set movement flags based on the layout manager 
    if (recyclerView.getLayoutManager() instanceof GridLayoutManager) { 
     final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT; 
     final int swipeFlags = 0; 
     return makeMovementFlags(dragFlags, swipeFlags); 
    } else { 
     final int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN; 
     final int swipeFlags = 0; 
     return makeMovementFlags(dragFlags, swipeFlags); 
    } 
} 

@Override 
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder source, RecyclerView.ViewHolder target) { 
    if (source.getItemViewType() != target.getItemViewType()) { 
     return false; 
    } 

    // Notify the adapter of the move 
    mAdapter.onItemMove(source.getAdapterPosition(), target.getAdapterPosition()); 
    return true; 
} 

@Override 
public void onSwiped(RecyclerView.ViewHolder viewHolder, int i) { 
    // Notify the adapter of the dismissal 
    mAdapter.onItemDismiss(viewHolder.getAdapterPosition()); 
} 

@Override 
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) { 
    if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) { 
     // Fade out the view as it is swiped out of the parent's bounds 
     final float alpha = ALPHA_FULL - Math.abs(dX)/(float) viewHolder.itemView.getWidth(); 
     viewHolder.itemView.setAlpha(alpha); 
     viewHolder.itemView.setTranslationX(dX); 
    } else { 
     super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive); 
    } 
} 

@Override 
public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) { 
    // We only want the active item to change 
    if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) { 
     if (viewHolder instanceof ItemTouchHelperViewHolder) { 
      // Let the view holder know that this item is being moved or dragged 
      ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder; 
      itemViewHolder.onItemSelected(); 
     } 
    } 

    super.onSelectedChanged(viewHolder, actionState); 
} 

@Override 
public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) { 
    super.clearView(recyclerView, viewHolder); 

    viewHolder.itemView.setAlpha(ALPHA_FULL); 

    if (viewHolder instanceof ItemTouchHelperViewHolder) { 
     // Tell the view holder it's time to restore the idle state 
     ItemTouchHelperViewHolder itemViewHolder = (ItemTouchHelperViewHolder) viewHolder; 
     itemViewHolder.onItemClear(); 
    } 
}} 

现在只需将此代码添加到您的回收观点适配器

recyclerView = (RecyclerView) findViewById(R.id.recycler_view); 
    recyclerView.setHasFixedSize(true); 
    recyclerView.setLayoutManager(new LinearLayoutManager(this));  

adapter = new RecyclerListAdapter(Activity_OutletSorting.this, onStartDragListener, olm_name,idopeningclosing); 
      recyclerView.setAdapter(adapter); 

      ItemTouchHelper.Callback callback = new SimpleItemTouchHelperCallback(adapter); 
      mItemTouchHelper = new ItemTouchHelper(callback); 
      mItemTouchHelper.attachToRecyclerView(recyclerView);