ItemTouchHelper：限制回收視圖中的ItemTocuchHelper.SimpleCallBack的滑動寬度

Question

我已成功實施滑動行爲並使用它執行了一些操作。現在我遇到的問題是我想限制滑動寬度，當我滑動項目。

目前，這是發生了什麼事

但我想限制滑動操作寬度到這裏

這是我迄今所做的： -

private void swipeExample(){ 
     ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) { 

      @Override 
      public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) { 
//    final int fromPos = viewHolder.getAdapterPosition(); 
//    final int toPos = target.getAdapterPosition(); 
       return false; 
      } 

      @Override 
      public void onSwiped(final RecyclerView.ViewHolder viewHolder, int swipeDir) { 

       // Show delete confirmation if swipped left 
       if (swipeDir == ItemTouchHelper.LEFT) { 

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); 
        builder.setMessage("Are you sure you want to delete?") 
          .setCancelable(false) 
          .setPositiveButton("Yes", new DialogInterface.OnClickListener() { 
           public void onClick(DialogInterface dialog, int id) { 
            deleteItem(viewHolder); 
//         getActivity().finish(); 
           } 
          }) 
          .setNegativeButton("No", new DialogInterface.OnClickListener() { 
           public void onClick(DialogInterface dialog, int id) { 
            dialog.cancel(); 
           } 
          }); 
        AlertDialog alert = builder.create(); 
        alert.show(); 

       } else if (swipeDir == ItemTouchHelper.RIGHT) { 
        // Show edit dialog 
       } 
      } 

      @Override 
      public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) { 

       Bitmap icon; 
       if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) { 

        View itemView = viewHolder.itemView; 
        float height = (float) itemView.getBottom() - (float) itemView.getTop(); 
        float width = height/3; 

        if (dX > 0) { 
         p.setColor(Color.parseColor("#388E3C")); 
         RectF background = new RectF((float) itemView.getLeft(), (float) itemView.getTop(), dX, (float) itemView.getBottom()); 
         c.drawRect(background, p); 
         icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_mode_edit_white_24dp); 
         RectF icon_dest = new RectF((float) itemView.getLeft() + width, (float) itemView.getTop() + width, (float) itemView.getLeft() + 2 * width, (float) itemView.getBottom() - width); 
         c.drawBitmap(icon, null, icon_dest, p); 
        } else if (dX < 0) { 
         p.setColor(Color.parseColor("#D32F2F")); 
         RectF background = new RectF((float) itemView.getRight() + dX, (float) itemView.getTop(), (float) itemView.getRight(), (float) itemView.getBottom()); 
         c.drawRect(background, p); 
         icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_delete_white_24dp); 
         RectF icon_dest = new RectF((float) itemView.getRight() - 2 * width, (float) itemView.getTop() + width, (float) itemView.getRight() - width, (float) itemView.getBottom() - width); 
         c.drawBitmap(icon, null, icon_dest, p); 
        } 
       } 
       super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive); 
      } 
     }; 

     ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback); 
     itemTouchHelper.attachToRecyclerView(recyclerView); 

    } 

請你能告訴我如何限制onChildDraw()方法的寬度。

在此先感謝。

Answer 1

末你onChildDraw()方法調用喜歡它的超級超級方法，以便：

super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive); 

要限制你可以調用super.onChildDraw()你刷卡的最大寬度減少dX：

super.onChildDraw(c, recyclerView, viewHolder, dX/4, dY, actionState, isCurrentlyActive);