滚动时更新recyclerview的位置（android）

如何更新滚动位置。现在每当我点击物品时，位置都会更新。我想每次滚动时更新位置。我想要做的是有一个文本视图，它将在滚动项目时得到更新。滚动时更新recyclerview的位置（android）

recyclerView.addOnItemTouchListener(new GalleryAdapter.RecyclerTouchListener(this, recyclerView, new GalleryAdapter.ClickListener() 
      { 

       @Override 
       public void onClick(View view, int position) { 

        Intent intent = new Intent(mainActivityCarasoul.this, PDFViewerActivity.class); 
        intent.putExtra(PDFViewerActivity.TAG, books.get(position)); 
        intent.putExtra("from", "mainActivityCarasoul"); 
        startActivity(intent); 
       } 
       @Override 
       public void onLongClick(View view, int position) { 
       } 
      })); 

      recyclerView.addOnScrollListener(new CenterScrollListener()); 

      recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
       @Override 
       public void onScrollStateChanged(RecyclerView recyclerView, int newState) { 
        super.onScrollStateChanged(recyclerView, newState); 
        // title.setText(books.get(position).getName()); 

       } 
      });

来源

2017-04-20 Khallad shahin

您onBindView持有人你是什么意思更新的位置？你需要描述你想要做得更清楚的事情。 –

我更新了问题 –

退房http://stackoverflow.com/questions/24989218/get-visible-items-in-recyclerview –

嗨，你可以使用下面的代码，

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() 
    { 
     @Override 
     public void onScrolled(RecyclerView recyclerView, int dx, int dy) 
     { 
      GridLayoutManager layoutManager = ((GridLayoutManager)mRecyclerView.getLayoutManager()); 
      int firstVisiblePosition = layoutManager.findFirstVisibleItemPosition(); 
      int findFirstCompletelyVisibleItemPosition = layoutManager.findFirstCompletelyVisibleItemPosition(); 
      int findLastVisibleItemPosition = layoutManager.findLastVisibleItemPosition(); 
      int findLastCompletelyVisibleItemPosition = layoutManager.findLastCompletelyVisibleItemPosition(); 
     } 
    });

来源

2017-04-20 04:31:56

我得到这个错误java.lang.ClassCastException：com.azoft.carousellayoutmanager.CarouselLayoutManager can not be强制转换为android.support.v7.widget.GridLayoutManager –

我认为你的setLayoutManager是CarouselLayoutManager，所以你可以在上面的代码中将GridLayoutManager更改为CarouselLayoutManager。即CarouselLayoutManager layoutManager =（（CarouselLayoutManager）mRecyclerView.getLayoutManager（））; –

是的，我试过，但我在这4行findFirstVisibleItemPosition（）; –

利用这一点，你必须保持你的活动，并在您的适配器类selectedItem属性为INT intialize previousPoistion = -1 previousPosition;和selectedPosition = 1;

@Override 
     public void onScrollStateChanged(RecyclerView recyclerView, int newState) { 
      super.onScrollStateChanged(recyclerView, newState); 
      switch (newState) { 
       case 0: 
        int pos = linearLayoutManager1.findLastVisibleItemPosition(); 
        yourAdapter.selectedPosition = pos - 1; 
        previousPosition = pos - 1; 
        yourTextView.setText(yourLIst.get(pos-1)); 
        break; 
      } 
     } 
    });

和适配器

@Override 
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) { 
if (position == selectedPosition) { 
      //do what you want when selected 
      } 
}

来源

2017-04-20 05:07:16

滚动时更新recyclerview的位置（android）

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