Android RecyclerView的notify方法和动画的刷新详解
Posted 路宇
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Android RecyclerView的notify方法和动画的刷新详解相关的知识，希望对你有一定的参考价值。
前些天发现了一个蛮有意思的人工智能学习网站,8个字形容一下"通俗易懂，风趣幽默"，感觉非常有意思,忍不住分享一下给大家。
👉点击跳转到教程
前言：
本篇讲解了RecyclerView关于通知列表刷新的常用的notify方法。和RecyclerView动画的简单详解。
首先看下效果图
1、页面对应的xml代码如下：
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="presenter"
type="com.example.customview.ui.RecyclerViewActivity.Presenter" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".ui.RecyclerViewActivity">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/btn_reset"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="重置"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btn_refresh_all"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="全部刷新"
app:layout_constraintStart_toEndOf="@id/btn_reset"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btn_refresh_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="刷新第2条"
app:layout_constraintStart_toEndOf="@id/btn_refresh_all"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btn_refresh_234"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="刷新第2,3,4条"
app:layout_constraintStart_toEndOf="@id/btn_refresh_2"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btn_part_refresh_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="局部刷新第2条"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_reset" />
<Button
android:id="@+id/btn_part_refresh_234"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="局部刷新第2,3,4条"
app:layout_constraintStart_toEndOf="@+id/btn_part_refresh_2"
app:layout_constraintTop_toBottomOf="@id/btn_reset" />
<Button
android:id="@+id/btn_insert_1_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="位置1插入一条"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_part_refresh_234" />
<Button
android:id="@+id/btn_insert_3_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="位置3插入两条"
app:layout_constraintStart_toEndOf="@id/btn_insert_1_1"
app:layout_constraintTop_toBottomOf="@id/btn_part_refresh_234" />
<Button
android:id="@+id/btn_move_2_4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="2移到4(都指的是索引)"
app:layout_constraintStart_toEndOf="@id/btn_insert_3_2"
app:layout_constraintTop_toBottomOf="@id/btn_part_refresh_234" />
<Button
android:id="@+id/btn_remove_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="删除第2条"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_move_2_4" />
<Button
android:id="@+id/btn_remove_234"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@(view)->presenter.onClick(view)"
android:text="删除第2,3,4条"
app:layout_constraintStart_toEndOf="@id/btn_remove_2"
app:layout_constraintTop_toBottomOf="@id/btn_move_2_4" />
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/rv_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:overScrollMode="never"
android:scrollbars="none" />
</LinearLayout>
</layout>
2、对应的适配器代码如下
/**
* @Author: ly
* @Date: 2023/3/9
* @Description: 适配器
*/
public class NotifyDataAdapter extends RecyclerView.Adapter<NotifyDataAdapter.NotifyDataViewHolder>
private List<NotifyModel> notifyModels = new ArrayList<>();
public NotifyDataAdapter(List<NotifyModel> notifyModels)
this.notifyModels = notifyModels;
@NonNull
@Override
public NotifyDataViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType)
ItemNotifyDataBinding binding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()), R.layout.item_notify_data, parent, false);
Log.i("TAG", "onCreateViewHolder: ");
return new NotifyDataViewHolder(binding);
@Override
public void onBindViewHolder(@NonNull NotifyDataViewHolder holder, int position)
Log.i("TAG", "onBindViewHolder:两个参数 " + position);
holder.bindData(position);
@Override
public void onBindViewHolder(@NonNull NotifyDataViewHolder holder, int position, @NonNull List<Object> payloads)
Log.i("TAG", "onBindViewHolder:三个参数 " + position);
if (payloads.isEmpty()) /** payloads为空说明不需要局部刷新,走原有的onBindViewHolder(holder, position) */
onBindViewHolder(holder, position);
else
for (Object o : payloads)
String payload = (String) o;
if ("title".equals(payload)) /** 只刷新title字段 */
holder.binding.tvTitle.setText(notifyModels.get(position).getTitle());
else if ("content".equals(payload)) /** 只刷新content字段 */
holder.binding.tvContent.setText(notifyModels.get(position).getContent());
@Override
public int getItemCount()
Log.i("TAG", "getItemCount: " + notifyModels.size());
return notifyModels.size();
@Override
public int getItemViewType(int position)
Log.i("TAG", "getItemViewType: " + position);
return super.getItemViewType(position);
public class NotifyDataViewHolder extends RecyclerView.ViewHolder
ItemNotifyDataBinding binding;
public NotifyDataViewHolder(@NonNull ItemNotifyDataBinding itemView)
super(itemView.getRoot());
binding = itemView;
public void bindData(int position)
binding.setModel(notifyModels.get(position));
Activity对应的代码如下，关于notify方法已经在注释中给出：
/**
* @Author: ly
* @Date: 2023/3/11
* @Description: RecyclerView常用notify方法
*/
public class RecyclerViewActivity extends AppCompatActivity
private ActivityRecyclerViewBinding binding;
private NotifyDataAdapter adapter;
private List<NotifyModel> notifyModels = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
binding = DataBindingUtil.setContentView(this, R.layout.activity_recycler_view);
binding.setPresenter(new Presenter());
initData();
// binding.rvList.setItemAnimator(null);//去掉默认动画
// binding.rvList.setItemAnimator(new SlideInLeftAnimator());
binding.rvList.setLayoutManager(new LinearLayoutManager(this));
adapter = new NotifyDataAdapter(notifyModels);
binding.rvList.setAdapter(adapter);
private void initData()
notifyModels.clear();
for (int i = 0; i < 5; i++)
notifyModels.add(new NotifyModel("第" + i + "个标题", "第" + i + "条详细内容,详细的信息"));
public class Presenter
public void onClick(View view)
if (view == binding.btnReset)
reset();
else if (view == binding.btnRefreshAll)
notifyAllData();
else if (view == binding.btnRefresh2)
notify_2();
else if (view == binding.btnRefresh234)
notify_234();
else if (view == binding.btnPartRefresh2)
notifyPart_2();
else if (view == binding.btnPartRefresh234)
notifyPart_234();
else if (view == binding.btnInsert11)
insert_1_1();
else if (view == binding.btnInsert32)
insert_3_2();
else if (view == binding.btnMove24)
move_2_4();
else if (view == binding.btnRemove2)
remove2();
else if (view == binding.btnRemove234)
remove234();
/**
* 删除索引为2,3,4条的数据
*/
private void remove234()
for (NotifyModel model : notifyModels)
model.setTitle("remove234" + model.getTitle());
model.setContent("remove234" + model.getContent());
NotifyModel model2 = notifyModels.get(2);
NotifyModel model3 = notifyModels.get(3);
NotifyModel model4 = notifyModels.get(4);
notifyModels.remove(model2);
notifyModels.remove(model3);
notifyModels.remove(model4);
//notifyItemRangeRemoved(int positionStart, int itemCount)
//从positionStart位置，itemCount数量的数据进行删除
adapter.notifyItemRangeRemoved(2, 3);
/**
* 删除索引为2的条目数据
*/
private void remove2()
for (NotifyModel model : notifyModels)
model.setTitle("remove2" + model.getTitle());
model.setContent("remove2" + model.getContent());
notifyModels.remove(2);
//notifyItemRemoved(int position)：列表position位置移除一条数据时调用。
adapter.notifyItemRemoved(2);
/**
* 2的位置移动到4
*/
private void move_2_4()
for (NotifyModel model : notifyModels)
model.setTitle("move_2_4" + model.getTitle());
model.setContent("move_2_4" + model.getContent());
//notifyItemMoved(int fromPosition, int toPosition)：将条目下标为fromPosition的位置
//移动到toPosition位置时调用。
adapter.notifyItemMoved(2, 4);
/**
* 在索引位置为3的位置，添加了两条数据
*/
private void insert_3_2()
for (NotifyModel model : notifyModels)
model.setTitle("insert_3_2" + model.getTitle());
model.setContent("insert_3_2" + model.getContent());
NotifyModel model = new NotifyModel("insert_3_2 add 3", "insert_3_2 add 3");
notifyModels.add(3, model);//在索引为3的位置，添加了一条数据
NotifyModel model1 = new NotifyModel("insert_3_2 add 4", "insert_3_2 add 4");
notifyModels.add(4, model1);//在索引为3的位置，添加了一条数据
//notifyItemRangeInserted(int positionStart, int itemCount)
//从指定的位置开始刷新，添加itemCount个数据
adapter.notifyItemRangeInserted(3, 2);
/**
* 索引为1处，插入1条数据
*/
private void insert_1_1()
for (NotifyModel model : notifyModels)
model.setTitle("insert_1_1" + model.getTitle());
model.setContent("insert_1_1" + model.getContent());
NotifyModel model = new NotifyModel("insert_1_1 add", "insert_1_1 add");
notifyModels.add(1, model);//在索引为1的位置，添加了一条数据
//notifyItemInserted(position):在position位置添加一条数据
adapter.notifyItemInserted(1);
/**
* 局部更新，下标为2开始的三条数据(包含2 那么其实就是2,3,4)
*/
private void notifyPart_234()
for (NotifyModel model : notifyModels)
model.setTitle("notifyPart_234" + model.getTitle());
model.setContent("notifyPart_234" + model.getContent());
NotifyModel model = new NotifyModel("notifyPart_234 add", "notifyPart_234 add");
notifyModels.add(model);
// notifyItemRangeChanged(int positionStart, int itemCount,
// @Nullable Object payload):从指定的位置开始刷新，指定个item
//payload用来标记需要局部刷新的部分。
adapter.notifyItemRangeChanged(2, 3, "content");
/**
* 局部更新，更新下标索引为2的条目，刷新其中的一个字段
*/
private void notifyPart_2()
for (NotifyModel model : notifyModels)
model.setTitle("notifyPart_2" + model.getTitle());
model.setContent("notifyPart_2" + model.getContent());
NotifyModel model = new NotifyModel("notifyPart_2 add", "notifyPart_2 add");
notifyModels.add(model);
//notifyItemChanged(int position, @Nullable Object payload):刷新指定位置
//payload用来标记需要局部刷新的部分。
adapter.notifyItemChanged(2, "title");//只局部刷新下标为2的条目数据 数据又新增了一条，这时也会被加载出来。
/**
* 刷新下标为2开始的三条数据(包含2 那么其实就是2,3,4)
*/
private void notify_234()
for (NotifyModel model : notifyModels)
model.setTitle("notify_2" + model.getTitle());
model.setContent("notify_2" + model.getContent());
NotifyModel model = new NotifyModel("notify_2 add", "notify_2 add");
notifyModels.add(model);
//notifyItemRangeChanged(int positionStart, int itemCount):从指定的位置开始刷新，指定个item
//item传1等价于notifyItemChanged(position)
adapter.notifyItemRangeChanged(2, 3);
/**
* 刷新下标位置为2的条目数据
*/
private void notify_2()
for (NotifyModel model : notifyModels)
model.setTitle("notify_2" + model.getTitle());
model.setContent("notify_2" + model.getContent());
NotifyModel model = new NotifyModel("notify_2 add", "notify_2 add");
notifyModels.add(model);
//notifyItemChanged(position):刷新指定位置
adapter.notifyItemChanged(2);//只刷新下标为2的条目数据 数据又新增了一条，这时也会被加载出来。
/**
* 重置
*/
private void reset()
initData();
adapter.notifyDataSetChanged();
/**
* 刷新全部
*/
public void notifyAllData()
for (NotifyModel model : notifyModels)
model.setTitle("notifyAll" + model.getTitle());
model.setContent("notifyAll" + model.getContent());
NotifyModel model = new NotifyModel("notifyAll add", "notifyAll add");
notifyModels.add(model);
adapter.notifyDataSetChanged();//刷新全部item
下面是调用不同的notify方法适配器执行的方法顺序如下：
对应上文
1、执行notifyAllData(),实际调用的是 notifyDataSetChanged 刷新全部，适配器执行方法如下
getItemCount: 6
getItemCount: 6
getItemCount: 6
getItemViewType: 0
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 1
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 2
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 3
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 4
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 5
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
2、执行notify_2(),实际调用的是 notifyItemChanged(2)，适配器执行方法如下
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
3、执行notify_234(),实际调用的是 notifyItemRangeChanged(2, 3);，适配器执行方法如下
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 3
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 4
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemViewType: 5
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
4、执行notifyPart_2(),实际调用的是 notifyItemChanged(2, “title”);，适配器执行方法如下
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
onBindViewHolder:三个参数
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
onCreateViewHolder:
onBindViewHolder:三个参数
onBindViewHolder:两个参数
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
getItemCount: 6
getItemViewType: 3
getItemCount: 6
getItemViewType: 4
getItemCount: 6
getItemViewType: 5
5、执行notifyPart_234(),实际调用的是notifyItemRangeChanged(2, 3, “content”);，适配器执行方法如下
getItemCount: 6
getItemCount: 6
getItemViewType: 0
getItemCount: 6
getItemViewType: 1
getItemCount: 6
getItemViewType: 2
onBindViewHolder:以上是关于Android RecyclerView的notify方法和动画的刷新详解的主要内容，如果未能解决你的问题，请参考以下文章
Android：RecyclerView里面的RecyclerView，滚动到底部
Android教程2020 - RecyclerView获取滑动距离
Android的import android.support.v7.widget.RecyclerView的RecyclerView标红问题