java–RecyclerView显示List上删除的数据

概述我已经实现了带有收件箱样式滑动视图的RecyclerView.刷卡时,我使用以下方法删除了列表项：publicvoidremoveItem(intposition){countries.remove(position);notifyItemRemoved(position);}类似地,当按下FAB时,我使用该方法添加数据,publicvoidaddItem(String

我已经实现了带有收件箱样式滑动视图的RecyclerVIEw.刷卡时,我使用以下方法删除了列表项：

public voID removeItem(int position) {    countrIEs.remove(position);    notifyItemRemoved(position);}

类似地,当按下FAB时,我使用该方法添加数据,

public voID addItem(String country) {    countrIEs.add(country);    notifyItemInserted(countrIEs.size());}

但是,当我通过滑动删除数据项时,它将从ArrayList和RecyclerVIEw列表中删除,但是当我通过FAB添加数据时,删除的数据仍会显示在列表中.我检查了ArrayList数据集.这是预期的.

在上面的屏幕截图中,您可以看到String Test是新添加的数据.我已经删除了最后两行的数据.随机显示.

我的适配器和活动的完整代码.

public class DataAdapter extends RecyclerVIEw.Adapter<DataAdapter.VIEwHolder> {    private ArrayList<String> countrIEs;    private TextVIEw tv_country;    public DataAdapter(ArrayList<String> countrIEs) {        this.countrIEs = countrIEs;    }    @OverrIDe    public DataAdapter.VIEwHolder onCreateVIEwHolder(VIEwGroup vIEwGroup, int i) {        VIEw vIEw = LayoutInflater.from(vIEwGroup.getContext()).inflate(R.layout.row_layout, vIEwGroup, false);        return new VIEwHolder(vIEw);    }    @OverrIDe    public voID onBindVIEwHolder(DataAdapter.VIEwHolder vIEwHolder, int i) {        tv_country.setText(countrIEs.get(i));    }    @OverrIDe    public int getItemCount() {        return countrIEs.size();    }    public voID addItem(String country) {        countrIEs.add(country);        notifyItemInserted(countrIEs.size());    }    public voID removeItem(int position) {        countrIEs.remove(position);        notifyItemRemoved(position);    }    public class VIEwHolder extends RecyclerVIEw.VIEwHolder{        public VIEwHolder(VIEw vIEw) {            super(vIEw);            tv_country = (TextVIEw)vIEw.findVIEwByID(R.ID.tv_country);        }    }}

MainActivity.java

public class MainActivity extends AppCompatActivity implements VIEw.OnClickListener{    private ArrayList<String> countrIEs =  new ArrayList<>();    private DataAdapter adapter;    private RecyclerVIEw recyclerVIEw;    private  RecyclerVIEw.LayoutManager layoutManager;    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(R.layout.activity_main);        initVIEws();    }    private voID initVIEws(){        floatingActionbutton fab = (floatingActionbutton) findVIEwByID(R.ID.fab);        fab.setonClickListener(this);        recyclerVIEw = (RecyclerVIEw)findVIEwByID(R.ID.card_recycler_vIEw);        recyclerVIEw.setHasFixedSize(true);        layoutManager = new linearlayoutmanager(getApplicationContext());        recyclerVIEw.setLayoutManager(layoutManager);        adapter = new DataAdapter(countrIEs);        recyclerVIEw.setAdapter(adapter);        countrIEs.add("Australia");        countrIEs.add("India");        countrIEs.add("United States of America");        countrIEs.add("Germany");        countrIEs.add("Russia");        adapter.notifyDataSetChanged();        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 voID onSwiped(RecyclerVIEw.VIEwHolder vIEwHolder, int direction) {                int position = vIEwHolder.getAdapterposition();                if (direction == itemtouchhelper.left){                    adapter.removeItem(position);                }            }            @OverrIDe            public voID onChildDraw(Canvas c, RecyclerVIEw recyclerVIEw, RecyclerVIEw.VIEwHolder vIEwHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {                Paint p = new Paint();                Bitmap icon;                if(actionState == itemtouchhelper.ACTION_STATE_SWIPE){                    VIEw itemVIEw = vIEwHolder.itemVIEw;                    if(dX > 0){                        p.setcolor(color.parsecolor("#388E3C"));                        c.drawRect((float) itemVIEw.getleft(), (float) itemVIEw.gettop(), dX,(float) itemVIEw.getBottom(), p);                        icon = BitmapFactory.decodeResource(                                getResources(), R.drawable.ic_edit_white);                        float height = (float) itemVIEw.getBottom() - (float) itemVIEw.gettop();                        float wIDth = height / 3;                        RectF dest = new RectF((float) itemVIEw.getleft() + wIDth ,(float) itemVIEw.gettop() + wIDth,(float) itemVIEw.getleft()+ wIDth+wIDth,(float)itemVIEw.getBottom() - wIDth);                        c.drawBitmap(icon,null,dest,p);                    } else {                        p.setcolor(color.parsecolor("#D32F2F"));                        c.drawRect((float) itemVIEw.getRight() + dX, (float) itemVIEw.gettop(),(float) itemVIEw.getRight(), (float) itemVIEw.getBottom(), p);                        icon = BitmapFactory.decodeResource(getResources(), R.drawable.ic_delete_white);                        float height = (float) itemVIEw.getBottom() - (float) itemVIEw.gettop();                        float wIDth = height / 3;                        RectF dest = new RectF((float) itemVIEw.getRight() - wIDth - wIDth ,(float) itemVIEw.gettop() + wIDth,(float) itemVIEw.getRight() - wIDth,(float)itemVIEw.getBottom() - wIDth);                        c.drawBitmap(icon,null,dest,p);                    }                }                super.onChildDraw(c, recyclerVIEw, vIEwHolder, dX, dY, actionState, isCurrentlyActive);            }        };        itemtouchhelper itemtouchhelper = new itemtouchhelper(simpleItemtouchCallback);        itemtouchhelper.attachToRecyclerVIEw(recyclerVIEw);    }    @OverrIDe    public voID onClick(VIEw v) {        switch (v.getID()){            case R.ID.fab:                adapter.addItem("Test");                Log.d("Raj",countrIEs.toString());                break;        }    }}

我试过了什么

我试过像这样使用notifyItemRangeChanged()：

public voID removeItem(int position) {    countrIEs.remove(position);    notifyItemRemoved(position);    notifyItemRangeChanged(position, countrIEs.size());}

解决方法:

我不能确定这会解决您的问题,但有一点不正确的是您如何绑定数据. tv_country不应该是DataAdapter的一部分;它应该是每个VIEwHolder的一部分.我们使用VIEwHolder模式的原因之一是保持对每行中视图的简单引用.

你的bind方法应该类似于：

public voID onBindVIEwHolder(DataAdapter.VIEwHolder vIEwHolder, int i) {    vIEwHolder.tv_country.setText(countrIEs.get(i));}

并确保将tv_country设置为内部VIEwHolder类的公共字段.

public class VIEwHolder extends RecyclerVIEw.VIEwHolder{    public TextVIEw tv_country;    public VIEwHolder(VIEw vIEw) {        super(vIEw);        tv_country = (TextVIEw) vIEw.findVIEwByID(R.ID.tv_country);    }}

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