Android 如何使用DiffUtils更新RecyclerView中的列表?
当使用DiffUtil ItemCallback时,如何使用DiffCallback在RecyclerView中加载新列表 我想给用户一个选项,当用户选择我希望RecyclerView更新的不同大小时,可以从数据库返回不同大小的列表 回收器Android 如何使用DiffUtils更新RecyclerView中的列表?,android,android-recyclerview,android-diffutils,Android,Android Recyclerview,Android Diffutils,当使用DiffUtil ItemCallback时,如何使用DiffCallback在RecyclerView中加载新列表 我想给用户一个选项,当用户选择我希望RecyclerView更新的不同大小时,可以从数据库返回不同大小的列表 回收器 RecyclerViewAdapter extends ListAdapter<WordEntity, RecyclerViewAdapter.ViewHolder> { private RecyclerViewAdapter() { s
RecyclerViewAdapter extends ListAdapter<WordEntity, RecyclerViewAdapter.ViewHolder> {
private RecyclerViewAdapter() {
super(DIFF_CALLBACK);
}
private static final DiffUtil.ItemCallback<WordEntity> DIFF_CALLBACK = new DiffUtil.ItemCallback<WordEntiti>() {
@Override
public boolean areItemsTheSame...
@Override
public boolean areContentsTheSame...
};
@Override
public viewHolder onCreateViewHolder...
@Override
public void onVindViewHolder ...
class ViewHolder extends RecyclerView.ViewHolder ...
public void updateWordList(List<WordEntity> words) {
final WordDiffCallBack diffCallBack = new WordDiffCallBack(list???, words);
final DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffCallBack);
this.list???.clear();
this.addAll(words);
diffResult.dispatcheUpdatesTo(this);
}
RecycleServiceAdapter扩展ListAdapter{
私人回收服务适配器(){
超级(差异回调);
}
私有静态final DiffUtil.ItemCallback DIFF_CALLBACK=new DiffUtil.ItemCallback(){
@凌驾
公共布尔项是相同的。。。
@凌驾
公共布尔值的内容相同。。。
};
@凌驾
公共视图持有者onCreateViewHolder。。。
@凌驾
公开无效的文件。。。
类ViewHolder扩展了RecyclerView.ViewHolder。。。
public void updateWordList(列出单词){
final WordDiffCallBack diffCallBack=新单词diffCallBack(列表??,单词);
最终DiffUtil.diffesult diffesult=DiffUtil.calculateDiff(diffCallBack);
此.list???.clear();
这个。addAll(单词);
衍射结果。发送更新至(本);
}
WordsDiffCallBack
private final List<WordEntity> mOldList;
private final List<WordEntity> mNewList;
public WordsDiffCallBack(List<WordEntity> oldList, List<WordEntity> newList) {
this.mOldList = oldList;
this.mNewList = newList;
}
@Override
public int getOldListSize() {
return mOldList.size();
}
@Override
public int getNewListSize() {
return mNewList.size();
}
@Override
public boolean areItemsTheSame(int OldItemPostion, int newItemPosition) ...
@Override boolean areContentsTheSame(int oldItemPosition, int newItemPosition)...
@Override getChangePayload(int oldItemPosition, int newItemPosition) ...
}
私人最终列表模具列表;
私人最终名单;
PublicWordsDiffCallback(列表oldList、列表newList){
this.mOldList=旧列表;
this.mNewList=newList;
}
@凌驾
public int getOldListSize(){
返回mOldList.size();
}
@凌驾
public int getNewListSize(){
返回mNewList.size();
}
@凌驾
公共布尔值areItemsTheSame(int-OldItemPosition,int-newItemPosition)。。。
@重写布尔值AreContentsSame(int-oldItemPosition,int-newItemPosition)。。。
@覆盖getChangePayload(int-oldItemPosition,int-newItemPosition)。。。
}
我希望RecycelView在用户更改列表大小时自动更新。如何从ListAdapter调用旧列表,这会更新RecyclerView吗
这是我的diffutil回调
public class MyDiffUtilCallback extends DiffUtil.Callback {
List<String> oldlist;
List<String > newlist;
public MyDiffUtilCallback(List<String> oldlist, List<String> newlist) {
this.oldlist = oldlist;
this.newlist = newlist;
}
@Override
public int getOldListSize() {
return oldlist.size();
}
@Override
public int getNewListSize() {
return newlist.size();
}
@Override
public boolean areItemsTheSame(int olditempostion, int newitemPostion) {
return olditempostion==newitemPostion;
}
@Override
public boolean areContentsTheSame(int olditempostion, int newitemPostion) {
return olditempostion==newitemPostion;
}
@Nullable
@Override
public Object getChangePayload(int oldItemPosition, int newItemPosition) {
return super.getChangePayload(oldItemPosition, newItemPosition);
}
public class recyclerviewAdapter extends RecyclerView.Adapter<recyclerviewAdapter.Viewholder> {
List<String> datasource;
public recyclerviewAdapter(List<String> datasource) {
this.datasource = datasource;
}
@Override
public Viewholder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.demorow,viewGroup,false);
return new Viewholder(itemView);
}
@Override
public void onBindViewHolder(@NonNull Viewholder viewholder, int i) {
viewholder.tv_demo_data_row.setText(datasource.get(i));
}
@Override
public int getItemCount() {
return datasource.size();
}
public static class Viewholder extends RecyclerView.ViewHolder {
TextView tv_demo_data_row;
public Viewholder(@NonNull View itemView) {
super(itemView);
tv_demo_data_row=itemView.findViewById(R.id.tv_demo_data_row);
}
}
//DIFF CALLBACK STATE
public void insertdata(List<String> insertList){
/**
* Insert list insert data to list
*/
MyDiffUtilCallback diffUtilCallback = new MyDiffUtilCallback(datasource,insertList);
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffUtilCallback);
datasource.addAll(insertList);
diffResult.dispatchUpdatesTo(this);
}
public void updateList(List<String> newList){
/**
* update list clear old data and update new data
*/
MyDiffUtilCallback diffUtilCallback = new MyDiffUtilCallback(datasource,newList);
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffUtilCallback);
datasource.clear();
datasource.addAll(newList);
diffResult.dispatchUpdatesTo(this);
}}
公共类MyDiffUtilCallback扩展了DiffUtil.Callback{
旧名单;
列表新建列表;
公共MyDiffUtilCallback(列表旧列表、列表新列表){
this.oldlist=oldlist;
this.newlist=newlist;
}
@凌驾
public int getOldListSize(){
返回oldlist.size();
}
@凌驾
public int getNewListSize(){
返回newlist.size();
}
@凌驾
公共布尔值areItemsTheSame(int-olditempostion、int-newitemPostion){
return olditempostion==newitemPostion;
}
@凌驾
公共布尔值是相同的内容(int-olditempostion、int-newitemPostion){
return olditempostion==newitemPostion;
}
@可空
@凌驾
公共对象getChangePayload(int-oldItemPosition、int-newItemPosition){
返回super.getChangePayload(oldItemPosition、newItemPosition);
}
}
这是使用DiffulicCallback的recyclerview Adpeter
public class MyDiffUtilCallback extends DiffUtil.Callback {
List<String> oldlist;
List<String > newlist;
public MyDiffUtilCallback(List<String> oldlist, List<String> newlist) {
this.oldlist = oldlist;
this.newlist = newlist;
}
@Override
public int getOldListSize() {
return oldlist.size();
}
@Override
public int getNewListSize() {
return newlist.size();
}
@Override
public boolean areItemsTheSame(int olditempostion, int newitemPostion) {
return olditempostion==newitemPostion;
}
@Override
public boolean areContentsTheSame(int olditempostion, int newitemPostion) {
return olditempostion==newitemPostion;
}
@Nullable
@Override
public Object getChangePayload(int oldItemPosition, int newItemPosition) {
return super.getChangePayload(oldItemPosition, newItemPosition);
}
public class recyclerviewAdapter extends RecyclerView.Adapter<recyclerviewAdapter.Viewholder> {
List<String> datasource;
public recyclerviewAdapter(List<String> datasource) {
this.datasource = datasource;
}
@Override
public Viewholder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.demorow,viewGroup,false);
return new Viewholder(itemView);
}
@Override
public void onBindViewHolder(@NonNull Viewholder viewholder, int i) {
viewholder.tv_demo_data_row.setText(datasource.get(i));
}
@Override
public int getItemCount() {
return datasource.size();
}
public static class Viewholder extends RecyclerView.ViewHolder {
TextView tv_demo_data_row;
public Viewholder(@NonNull View itemView) {
super(itemView);
tv_demo_data_row=itemView.findViewById(R.id.tv_demo_data_row);
}
}
//DIFF CALLBACK STATE
public void insertdata(List<String> insertList){
/**
* Insert list insert data to list
*/
MyDiffUtilCallback diffUtilCallback = new MyDiffUtilCallback(datasource,insertList);
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffUtilCallback);
datasource.addAll(insertList);
diffResult.dispatchUpdatesTo(this);
}
public void updateList(List<String> newList){
/**
* update list clear old data and update new data
*/
MyDiffUtilCallback diffUtilCallback = new MyDiffUtilCallback(datasource,newList);
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffUtilCallback);
datasource.clear();
datasource.addAll(newList);
diffResult.dispatchUpdatesTo(this);
}}
公共类RecycleServiceAdapter扩展了RecyclerView.Adapter{
列出数据源;
公共RecycleServiceAdapter(列表数据源){
this.datasource=数据源;
}
@凌驾
public Viewholder onCreateViewHolder(@NonNull ViewGroup ViewGroup,int i){
View itemView=LayoutFlater.from(viewGroup.getContext()).inflate(R.layout.demorow,viewGroup,false);
返回新的Viewholder(itemView);
}
@凌驾
public void onBindViewHolder(@NonNull Viewholder Viewholder,int i){
viewholder.tv_demo_data_row.setText(datasource.get(i));
}
@凌驾
public int getItemCount(){
返回datasource.size();
}
公共静态类Viewholder扩展了RecyclerView.Viewholder{
TextView tv\u demo\u data\u行;
公共视图持有者(@NonNull View itemView){
超级(项目视图);
tv\u demo\u data\u row=itemView.findviewbyd(R.id.tv\u demo\u data\u row);
}
}
//差异回调状态
公共void insertdata(列表insertList){
/**
*插入列表将数据插入列表
*/
MyDiffUtilCallback diffUtilCallback=新的MyDiffUtilCallback(数据源,插入列表);
DiffUtil.DiffiesUlt DiffiesUlt=DiffUtil.calculateDiff(diffUtilCallback);
addAll(insertList);
diffResult.dispatchUpdatesTo(本);
}
公共无效更新列表(列表新建列表){
/**
*更新列表清除旧数据并更新新数据
*/
MyDiffUtilCallback diffUtilCallback=新的MyDiffUtilCallback(数据源,newList);
DiffUtil.DiffiesUlt DiffiesUlt=DiffUtil.calculateDiff(diffUtilCallback);
datasource.clear();
addAll(newList);
diffResult.dispatchUpdatesTo(本);
}}
在这里,我可以更新按钮clickevent活动中的列表
insert_data.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//inserting the data
List<String> insertlist = new ArrayList<>(); //asign old list
for(int i=0;i<2;i++){
insertlist.add(UUID.randomUUID().toString()); // insert new list
adapter.insertdata(insertlist);
faster_recyclerview.smoothScrollToPosition(adapter.getItemCount()-1); //auto scroll to last postion
}
}
});
insert_data.setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
//插入数据
List insertlist=new ArrayList();//asign旧列表
对于(int i=0;i,您可以创建一个模板,如youTube上的视频所示:
下面是适配器的一个示例
public class CartFragAdapter extends RecyclerView.Adapter<CartFragAdapter.CartFragViewHolder> {
private static final String TAG = "debinf PurchaseAdap";
private static final DiffUtil.ItemCallback<ProductsObject> DIFF_CALLBACK = new DiffUtil.ItemCallback<ProductsObject>() {
@Override
public boolean areItemsTheSame(@NonNull ProductsObject oldProduct, @NonNull ProductsObject newProduct) {
Log.i(TAG, "areItemsTheSame: old is "+oldProduct.getCode()+" ; new is "+newProduct.getCode());
return oldProduct.getCode().equals(newProduct.getCode());
}
@Override
public boolean areContentsTheSame(@NonNull ProductsObject oldProduct, @NonNull ProductsObject newProduct) {
Log.i(TAG, "areContentsTheSame: old is "+oldProduct.getPrice()+" ; new is "+newProduct.getPrice());
return oldProduct.getPrice() == newProduct.getPrice();
}
};
private AsyncListDiffer<ProductsObject> differ = new AsyncListDiffer<ProductsObject>(this, DIFF_CALLBACK);
@NonNull
@Override
public CartFragViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_purchase, parent, false);
return new CartFragViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull CartFragViewHolder holder, int position) {
final ProductsObject purchaseList = differ.getCurrentList().get(position);
holder.mCode.setText(purchaseList.getCode());
holder.mPrice.setText(String.valueOf(purchaseList.getPrice()));
holder.mDescription.setText(purchaseList.getDescription());
}
@Override
public int getItemCount() {
Log.i(TAG, "getItemCount");
return differ.getCurrentList().size();
}
public void submitList(List<ProductsObject> products){
Log.i(TAG, "submitList: products.size is "+products.size());
differ.submitList(products);
}
public class CartFragViewHolder extends RecyclerView.ViewHolder {
public TextView mCode, mPrice, mDescription;
public CartFragViewHolder(@NonNull View itemView) {
super(itemView);
mCode = (TextView) itemView.findViewById(R.id.item_productCode);
mPrice = (TextView) itemView.findViewById(R.id.item_productPrice);
mDescription = (TextView) itemView.findViewById(R.id.item_productDescription);
}
}
}
我希望它能有所帮助!除上述内容外(使用DiffUtils),如果您使用单击更改RecyclerView的内容,请
ViewHolder implements View.OnClickListener
并使用此选项在onBindViewHolder中设置OnClickListener
.setOnClickListener(holder);
并通过
this.getAdapterPosition()
私有类HistoryRecyclerAdapter扩展了RecyclerView.Adapter{
私人名单条目;
HistoryRecyclerAdapter(列表条目){
this.entries=条目;
}
公共无效更新容器(列表){
DiffUtil.diffesult diffesult=DiffUtil.calculateDiff(新的DiffUtil.Callback(){
@凌驾
public int getOldListSize(){return entries.size();}
@凌驾
public int getNewListSize(){return list.size();}
@凌驾
公共布尔值areItemsTheSame(int-oldItemPosition,int-newItemPosition){
返回条目.get(oldItemPosition).getId()==list.get(newItemPosition).getId();
}
@凌驾
公共布尔值是相同的内容(int oldItemP