如何在RecyclerView中制作假刷卡

Question

就像您不能忽视的那些通知：您一直滑到中间，然后停止。有谁知道如何在RecyclerView中做到这一点？

如果你不记得：
https://youtu.be/eFvhFkZfGlA

Answer 1

ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) { 
     @Override 
     public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) { 
      return false; 
     } 

     @Override 
     public float getSwipeThreshold(RecyclerView.ViewHolder viewHolder) { 
      return 1; 
     } 
    }; 

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

这里的关键部分是 getSwipeThreshold方法 。

----------------------------------
编辑：其实，有一个更重要的是，我无法找到一种方法来准确实现所要求的内容（完全像视频和Android通知栏），但由于我在这里有错误的答案，我决定编辑我的文章并实施一些与它。

除了在ItemTouchHelper.SimpleCallback类中提及的内容和字段外，还有其他方法可以被覆盖。

领域：

 private final float stopPoint = 200;    // The point where items stop when move past it 
     private final float swipeStopFraction = 0.002f;  // higher means items stop sooner when swiped 
     private final float swipeSpeedFraction = 0.8f;  // lower means items move slower when swiped 

     private float prevA = 1; 
     private float a = 1; 

     private float prevDX; 
     private float backDX; 

     private boolean leftLock = false; 
     private boolean rightLock = false; 
     private boolean leftExpanded = false; 
     private boolean rightExpanded = false; 

     private CustomRecyclerViewAdapter.CustomViewHolder prevHolder; 

其他方法：

 @Override 
     public float getSwipeVelocityThreshold(float defaultValue) { 
      return 0; 
     } 

     @Override 
     public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) { 
      final CustomRecyclerViewAdapter.CustomViewHolder holder = (CustomRecyclerViewAdapter.CustomViewHolder) viewHolder; 
      prevHolder = holder; 

      dX *= swipeSpeedFraction; 

      if (!isCurrentlyActive) { 
       if (!leftLock) { 
        leftExpanded = false; 
       } 
       if (!rightLock) { 
        rightExpanded = false; 
       } 
       a = 0; 
      } 

      if (isCurrentlyActive) { 
       if (dX > 0 && !rightExpanded) { 
        leftExpanded = true; 
       } 
       if (dX < 0 && !leftExpanded) { 
        rightExpanded = true; 
       } 
      } 

      float cachedDX = dX; 
      if (a == 0) { 
       if (dX/prevA > stopPoint && !rightExpanded && backDX == 0) { 
        leftLock = true; 
        leftExpanded = true; 
       } 
       if (dX/prevA < -stopPoint && !leftExpanded && backDX == 0) { 
        rightLock = true; 
        rightExpanded = true; 
       } 
       if (backDX != 0) { 
        dX += backDX - dX; 
        backDX /= 2; 
       } else { 
        dX /= prevA; 
       } 
       a = 1; 
      } else if (dX == 0) { 
       backDX = 0; 
      } else if (dX > 0) { 
       if (leftExpanded) { 
        if (backDX != 0) { 
         leftLock = true; 
        } 
        dX /= a; 
        prevA = a; 
        a += swipeStopFraction * (cachedDX - prevDX); 
       } else { 
        dX = - stopPoint + dX; 
        if (backDX > 0) { 
         a += 0.01 * (cachedDX - prevDX); 
        } 
        dX /= a; 
        backDX = dX; 
        rightLock = false; 
       } 
      } else if (dX < 0) { 
       if (rightExpanded) { 
        if (backDX != 0) { 
         rightLock = true; 
        } 
        dX /= a; 
        prevA = a; 
        a -= swipeStopFraction * (cachedDX - prevDX); 
       } else { 
        dX = stopPoint + dX; 
        if (backDX < 0) { 
         a -= 0.01 * (cachedDX - prevDX); 
        } 
        dX /= a; 
        prevA = a; 
        backDX = dX; 
        leftLock = false; 
       } 
      } 
      prevDX = cachedDX; 

      if (leftLock) { 
       if (dX < stopPoint) { 
        dX = stopPoint; 
       } 
      } 

      if (rightLock) { 
       if (dX > -stopPoint) { 
        dX = -stopPoint; 
       } 
      } 

      // Below lines provide background for the empty area when the item is swiped. 
      // Container could be any layout that is the root layout if the item 
      final Paint paint = new Paint(); 
      paint.setColor(getResources().getColor(R.color.colorAccent)); 
      if (dX > 0) { 
       c.drawRect(holder.container.getLeft(), holder.container.getTop(), dX, holder.container.getBottom(), paint); 
      } else { 
       c.drawRect(holder.container.getRight() + dX, holder.container.getTop(), holder.container.getRight(), holder.container.getBottom(), paint); 
      } 


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

     @Override 
     public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) { 
      super.onSelectedChanged(viewHolder, actionState); 

      if (prevHolder != null && viewHolder != null && prevHolder != viewHolder) { 
       leftLock = false; 
       rightLock = false; 
       leftExpanded = false; 
       rightExpanded = false; 
       prevHolder.container.setTranslationX(0); // Container could be any layout that is the root layout if the item 
      } 

     } 

过的回收鉴于这是怎么回事的控制是非常有限的，我不能进一步推它的任何。我希望这可能会有所帮助。

就我个人而言，我认为这样做与ItemTouchHelper是非常难以实施和管理，结果将不会被接受。