RecyclerView项目位置在滚动时更改或删除

Question

我有一个问题，我一直试图解决太久，但我无法知道是什么原因导致问题。

我有一个标记列表，其中包含测试对象和主题字符串，我用它们作为标记之间的区域，我使用getClass（）方法确定对象是字符串还是测试，如果是字符串，我隐藏测试的RelativeLayout，如果它是一个测试，然后我隐藏该主题的RelativeLayout。但是当滚动时，项目被删除并随机重新添加。

我的适配器的类：

public class MarksAdapter extends RecyclerView.Adapter<MarksAdapter.MyHolder>{ 

public class MyHolder extends RecyclerView.ViewHolder{ 
    RelativeLayout card; 
    TextView title; 
    TextView total; 
    View divider; 
    int posito; 

    RelativeLayout group; 
    TextView groupTitle; 
    TextView groupMark; 

    public MyHolder(View itemView) { 
     super(itemView); 
     this.card = (RelativeLayout)itemView.findViewById(R.id.card); 
     this.title = (TextView)itemView.findViewById(R.id.title); 
     this.total = (TextView)itemView.findViewById(R.id.mark); 
     this.divider = itemView.findViewById(R.id.item_divider); 

     this.group = (RelativeLayout)itemView.findViewById(R.id.group); 
     this.groupTitle = (TextView)itemView.findViewById(R.id.group_title); 
     this.groupMark = (TextView)itemView.findViewById(R.id.group_mark); 

    } 
} 


final ArrayList marks; 
Context ctx; 
String selectedSem; 
TestDatabase db; 

public MarksAdapter(Context c, ArrayList marks,String sem,TestDatabase db,ArrayList<Integer> sections){ 
    this.marks = marks; 
    ctx = c; 
    selectedSem = sem; 
    this.db = db; 
} 

@Override 
public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

     return new MyHolder(LayoutInflater.from(ctx).inflate(R.layout.mark_child, parent, false)); 
} 

int lastPosition = -1; 
int offset = 0; 

@Override 
public void onBindViewHolder(final MyHolder holder, final int positioner) { 
    holder.posito = positioner; 
     if(marks.get(holder.posito).getClass() == Test.class) { 
      holder.group.setVisibility(View.GONE); 
      //mark 
      final Test test = (Test)marks.get(positioner); 
      holder.title.setText(test.getName()); 
      holder.total.setText(String.format(ctx.getString(R.string.new_m_sum), test.getMarkGot(), test.getMarkOver())); 

      //add here 
      holder.card.setOnClickListener(new View.OnClickListener() { 
       @Override 
       public void onClick(View v) { 
        Intent i = new Intent(ctx,addTest.class); 
        Test mark = (Test)marks.get(holder.posito); 
        i.putExtra("t_name",mark.getName()); 
        i.putExtra("subject",mark.getSubject()); 
        i.putExtra("mark_got",mark.getMarkGot()); 
        i.putExtra("mark_over",mark.getMarkOver()); 
        i.putExtra("mode","edit"); 
        i.putExtra("oldId", mark.getId()); 
        ctx.startActivity(i); 
       } 
      }); 

      holder.card.setLongClickable(true); 
      holder.card.setOnLongClickListener(new View.OnLongClickListener() { 
       @Override 
       public boolean onLongClick(final View v) { 
        final Dialog dialo = new Dialog(ctx); 
        dialo.requestWindowFeature(Window.FEATURE_NO_TITLE); 
        dialo.setContentView(R.layout.material_dialog); 
        TextView title = (TextView) dialo.findViewById(R.id.title); 

        TextView body = (TextView) dialo.findViewById(R.id.body); 

        Button negative = (Button) dialo.findViewById(R.id.negative); 
        negative.setText(ctx.getString(R.string.cancel)); 
        Button positive = (Button) dialo.findViewById(R.id.positive); 
        positive.setText(ctx.getString(R.string.Delete)); 

        title.setText(ctx.getString(R.string.d)); 
        body.setText(ctx.getString(R.string.q_delete) + " " + test.getName() + " " + ctx.getString(R.string.de_comp)); 

        negative.setOnClickListener(new View.OnClickListener() { 
         @Override 
         public void onClick(View v) { 
          dialo.dismiss(); 
         } 
        }); 

        positive.setOnClickListener(new View.OnClickListener() { 
         @Override 
         public void onClick(View vir) { 

          TestDatabase tb = new TestDatabase(ctx); 
          SemesterDatabase semesterDatabase = new SemesterDatabase(ctx); 
          tb.deleteTest(holder.posito, semesterDatabase.getSelected().getName()); 
          MarksAdapter.this.notifyItemRemoved(holder.posito); 

          marks.remove(holder.posito); 

          for (int i = 0; i < marks.size(); i++) { 
           if(!(marks.get(i) instanceof Test)) { 
            String sub = String.valueOf(marks.get(i)); 
            if(db.isNoValue(sub,selectedSem)){ 
             marks.remove(i); 
             notifyItemRemoved(i); 
            } 
           } 

          } 


          dialo.dismiss(); 
         } 
        }); 
        dialo.show(); 

        return true; 
       } 
      }); 
     }else { 
      holder.group.setVisibility(View.VISIBLE); 
      holder.card.setVisibility(View.GONE); 
     //group 
      if(holder.posito == 0) { 
       LinearLayout.LayoutParams params = (LinearLayout.LayoutParams)holder.group.getLayoutParams(); 
       params.setMargins(0,0,0,0); 
       holder.group.setLayoutParams(params); 
      } 
      String sub = String.valueOf(marks.get(holder.posito)); 
      holder.groupTitle.setText(sub); 
      holder.groupMark.setText(db.getTotalSubjectMarks(sub,selectedSem)); 
     } 


    if(lastPosition < holder.posito) { 
     if(holder.card.getVisibility() == View.VISIBLE) { 
      Animation slide = AnimationUtils.loadAnimation(ctx, R.anim.marks); 
      slide.setInterpolator(new AccelerateInterpolator()); 
      slide.setDuration(700); 
      offset += 100; 
      slide.setStartOffset(offset); 
      holder.card.startAnimation(slide); 
     } else { 
      Animation slide = AnimationUtils.loadAnimation(ctx, R.anim.mark_groups); 
      slide.setInterpolator(new AccelerateInterpolator()); 
      slide.setDuration(700); 
      offset += 50; 
      slide.setStartOffset(offset); 
      holder.group.startAnimation(slide); 
      } 
     lastPosition = holder.posito; 
    } 
    } 


@Override 
public int getItemCount() { 
    return marks.size(); 
} 
} 

注：我已经尝试过itemViewType方法，但它并没有为我

提前感谢合作！

Answer 1

我相信你错过了返回设定的holder.card可见，这样

if(marks.get(holder.posito).getClass() == Test.class) { 
     holder.card.setVisibility(View.Visible); //add back this 
     holder.group.setVisibility(View.GONE);