我有一个RecyclerView，显示带有复选框的图像。选中复选框后，与图像关联的项目将保存到数据库中。我还有一个字母索引，当点击它时，调用一个过滤图像的功能，并更新回收者视图，以显示标题对应于单击字母的图像。问题是RecyclerView图像仅在第一次单击时更新。随后的点击次数没有对RecyclerView图像进行更新。我已经检查过，看起来函数确实被随后的点击调用，因为我能够在函数的各个点显示Toast消息。只有RecyclerView没有使用过滤后的图像数据进行更新，我不知道它为什么不更新。任何有关这方面的帮助将不胜感激。
以下是主要活动：
public class AddBrandPage extends AppCompatActivity implements OnClickListener {
//declare variables
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
private RecyclerView.Adapter adapter;
private RecyclerView alpharecyclerView;
private RecyclerView.LayoutManager alphaLayoutManager;
private RecyclerView.Adapter alphaAdapter;
private DatabaseReference myRef;
private DatabaseReference userRef;
private Button btn_skip;
private Button btn_save;
private CheckBox checkbox;
private String t;
private String letter;
List<LogoItems> brandLogo = new ArrayList<>();
//HashMap<String, String> saveBrands = new HashMap<>();
List<LogoItems> removedBrandLogo = new ArrayList<>();
List<String> selectionList = new ArrayList<>();
List<AlphaItems> alphaList = new LinkedList<>();
List<LogoItems> tmp = new ArrayList<>();
String[] alphabets = {"All", "A", "B", "C", "D", "E", "F", "G", "H", "I",
"J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_brand_page);
//initialize variables
btn_skip = (Button) findViewById(R.id.btn_skip);
btn_save = (Button) findViewById(R.id.btn_save);
myRef = FirebaseDatabase.getInstance().getReference().child("/brands");
userRef = FirebaseDatabase.getInstance().getReference().child("/users");
//calls to load data to arraylists
loadAlpha();
loadLogoImgData();
//set the listener for the buttons click event
btn_skip.setOnClickListener(this);
btn_save.setOnClickListener(this);
}
private void loadAlpha() {
for (String alpha : alphabets) {
alphaList.add(new AlphaItems(alpha));
}
startAlphaRecyclerView();
}
public void loadLogoImgData() {
brandLogo.clear();
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot brandSnapshot : dataSnapshot.getChildren()) {
LogoItems value = brandSnapshot.getValue(LogoItems.class);
brandLogo.add(value);
tmp.add(value);
}
startLogoRecyclerView();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public void onClick(View view) {
if (view == btn_skip) {
//if skip button clicked close current window and go to user main page
finish();
startActivity(new Intent(getApplicationContext(), UserMainPage.class));
}
if (view == btn_save) {
saveData();
}
}
public void startLogoRecyclerView() {
// set the main recyclerview view for the logo in the layout
recyclerView = (RecyclerView) findViewById(R.id.recylView);
recyclerView.setHasFixedSize(true);
// set the main layoutManager of the logo recyclerview
layoutManager = new GridLayoutManager(this, 2);
recyclerView.setLayoutManager(layoutManager);
// set the logo recycler view adapter
adapter = new LogoAdapter(brandLogo, getBaseContext(), AddBrandPage.this);
recyclerView.setAdapter(adapter);
}
public void startAlphaRecyclerView() {
// set the main recyclerview view for the logo in the layout
alpharecyclerView = (RecyclerView) findViewById(R.id.alpharecyclerView);
alpharecyclerView.setHasFixedSize(true);
// set the main layoutManager of the alpha recyclerview
alphaLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
alpharecyclerView.setLayoutManager(alphaLayoutManager);
// set the alpha recycler view adapter
alphaAdapter = new AlphaAdapter(alphaList, getBaseContext(), AddBrandPage.this);
alpharecyclerView.setAdapter(alphaAdapter);
}
public List<String> prepareSelection(View v, int position) {
checkbox = (CheckBox) v;
//check if user selected checkbox and add or remove from list
//if (checkbox.isChecked()) {
selectionList.add(brandLogo.get(position).getName());
//} else {
// selectionList.remove(brandLogo.get(position).getLogo());
//}
return selectionList;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof AddBrandPage)) return false;
AddBrandPage that = (AddBrandPage) o;
if (t != null ? !t.equals(that.t) : that.t != null) return false;
return letter != null ? letter.equals(that.letter) : that.letter == null;
}
@Override
public int hashCode() {
int result = t != null ? t.hashCode() : 0;
result = 31 * result + (letter != null ? letter.hashCode() : 0);
return result;
}
public void updateLogoDisplay(final String letter) {
int i = 0;
brandLogo.clear();
brandLogo.addAll(tmp);
if (!(letter.equals("All"))) {
//Iterator<LogoItems> iter = brandLogo.iterator();
for (i=0; i< tmp.size(); i++){ //Iterator<LogoItems> iter = tmp.iterator(); iter.hasNext(); ) {
//while (iter.hasNext()) {
LogoItems r = tmp.get(i);
final String c = r.getName();
if (c != null) {
String t = c.substring(0, 1);
if (t != null) {
if (c != null) {
if ((letter.equals(t))) {
//brandLogo.remove(r);
removedBrandLogo.add(r);
//iter.remove();
}
}
}
} else {
}
}
brandLogo.clear();
brandLogo.addAll(removedBrandLogo);
adapter.notifyDataSetChanged();
//startLogoRecyclerView();
}
}
public void saveData() {
final FirebaseAuth mAuth;
final DatabaseReference userRef;
mAuth = FirebaseAuth.getInstance();
userRef = FirebaseDatabase.getInstance().getReference().child("users");
DatabaseReference curUser = userRef.child(mAuth.getCurrentUser().getUid());
curUser.child("brands").setValue(selectionList);//save selected items to the database
}
}
这是字母表适配器（AlphaAdapter.java）：
public class AlphaAdapter extends RecyclerView.Adapter<AlphaAdapter.AlphaViewHolder> {
//declare variables
List<AlphaItems> alphaList = new ArrayList<>();
private AddBrandPage addBrandPage;
private Context context;
//the constructor
public AlphaAdapter (List<AlphaItems> alphaList, Context context, AddBrandPage addBrandPage){
this.alphaList = alphaList;
this.context = context;
this.addBrandPage = addBrandPage;
}
@Override
public AlphaAdapter.AlphaViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.alpha_items, parent, false);
AlphaViewHolder alphaViewHolder = new AlphaViewHolder(view,addBrandPage);
return alphaViewHolder;
}
@Override
public void onBindViewHolder(AlphaAdapter.AlphaViewHolder holder, int position) {
holder.txt_alpha.setText(alphaList.get(position).getLetter());
}
@Override
public int getItemCount() {
return alphaList.size();
}
public class AlphaViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
//declare variables
private TextView txt_alpha;
private AddBrandPage addBrandPage;
//the constructor
public AlphaViewHolder (View itemView, AddBrandPage addBrandPage){
super(itemView);
this.addBrandPage = addBrandPage;
//initialize variables
txt_alpha = (TextView) itemView.findViewById(R.id.txt_alpha);
//set click listener
txt_alpha.setOnClickListener(this);
}
@Override
public void onClick(View v) {
int position = getAdapterPosition();
String letter = alphaList.get(position).getLetter();
addBrandPage.updateLogoDisplay(letter);
}
}
}
这是字母索引布局（alpha_items.xml）：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="40dp"
android:layout_height="match_parent"
android:scrollbars="horizontal">
<android.support.v7.widget.CardView
android:layout_width="40dp"
android:layout_height="40dp"
android:scrollbars="horizontal"
>
<TextView
android:id="@+id/txt_alpha"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_gravity="center_vertical"
android:layout_marginLeft="15dp"
android:layout_marginRight="2dp"
android:text="A"
android:textSize="18dp"
android:focusable="false"
android:focusableInTouchMode="false"
android:gravity="center_vertical"
/>
</android.support.v7.widget.CardView>
</LinearLayout>
以下是显示图像的徽标适配器（LogoAdapter.java）：
public class LogoAdapter extends RecyclerView.Adapter<LogoAdapter.LogoViewHolder> {
public static LogoAdapter adapter;
//declaration fo variables
List<LogoItems> brandLogo = new ArrayList<>();
List<String> selector = new ArrayList<>();
private AddBrandPage addBrandPage;
private Context context;
private CheckBox checkbox;
//the constructor
public LogoAdapter(List<LogoItems> brandLogo, Context context, AddBrandPage addBrandPage) {
this.brandLogo = brandLogo;
this.context = context;
this.addBrandPage = addBrandPage;
}
@Override
public LogoAdapter.LogoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.logo_items, parent, false);
LogoViewHolder logoViewHolder = new LogoViewHolder(view,addBrandPage);
return logoViewHolder;
}
@Override
public void onBindViewHolder(LogoAdapter.LogoViewHolder holder, int position) {
Picasso.with(context).load(brandLogo.get(position).getLogo()).into(holder.logo);
}
@Override
public int getItemCount() {
return brandLogo.size();
}
//viewholder class
public class LogoViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
//declare variables
private AddBrandPage addBrandPage;
private ImageView logo;
private CheckBox checkbox;
//ViewHolder constructor
public LogoViewHolder(View itemView, AddBrandPage addBrandPage) {
super(itemView);
//initialize variables inside the viewholder constructor
this.addBrandPage = addBrandPage;
logo = (ImageView) itemView.findViewById(R.id.img_logo);
checkbox = (CheckBox) itemView.findViewById(R.id.checkbox);
//set click listener for the checkbox
checkbox.setOnClickListener(this);
logo.setOnClickListener(this);
}
@Override
public void onClick(View v) {
int position = getAdapterPosition();
addBrandPage.prepareSelection(v, position);//method call to populate an arraylist with selected items
}
}
}
这是图像的xml布局（Logo_items.xml）
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:cardView="http://schemas.android.com/apk/res-auto"
android:id="@+id/logo_container"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="@android:color/darker_gray"
android:gravity="center_vertical|center_horizontal"
android:orientation="vertical"
android:paddingBottom="10dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="10dp"
android:visibility="visible"
cardView:layout_collapseParallaxMultiplier="1.0">
<android.support.v7.widget.CardView
android:layout_width="155dp"
android:layout_height="100dp"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp"
cardView:cardBackgroundColor="@android:color/white">
<GridLayout
android:id="@+id/cardView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal|center_vertical"
android:orientation="vertical">
<ImageView
android:id="@+id/img_logo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_column="1"
android:layout_gravity="center_horizontal|center_vertical"
android:layout_row="0"
android:paddingBottom="5dp"
android:paddingLeft="2.5dp"
android:paddingRight="2.5dp"
android:paddingTop="5dp">
</ImageView>
</GridLayout>
<CheckBox
android:id="@+id/checkbox"
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_marginLeft="130dp"
android:layout_marginTop="66dp"
android:onClick="addBrandpage.prepareSelection"
/>
</android.support.v7.widget.CardView>
</LinearLayout>
这是logcat：
06-16 09:16:24.404 12319-12324/com.test.test I/art: Do partial code cache collection, code=499KB, data=310KB
06-16 09:16:24.429 12319-12324/com.test.test I/art: After code cache collection, code=499KB, data=315KB
06-16 09:16:24.429 12319-12324/com.test.test I/art: Increasing code cache capacity to 2MB
06-16 09:16:32.258 12319-12326/com.test.test W/art: Suspending all threads took: 13.640ms
06-16 09:16:32.260 12319-12319/com.test.test I/Choreographer: Skipped 53 frames! The application may be doing too much work on its main thread.
答案 0 :(得分：0)
我能够解决问题。
活动页面上有两个OnClickListeners。一个用于checkboxes，一个用于字母索引。发生的事情是，当点击一个字母表时，OnClickListeners都会被触发。因此，在第一次点击时，字母OnClickListener执行完成，RecyclerView更新过滤后的图像。但是在第二次单击时，当它似乎执行该函数时，该函数没有完全完成，因为程序与checkbox OnClickListener混淆。解决方案是在onClick方法中添加if（条件），以便程序知道点击适用于哪个OnClickListener。 AlphaAdapter类中的修改如下：
@Override
public void onClick(View view) {
if (view == txt_alpha) {
int position = getAdapterPosition();
String letter = alphaList.get(position).getLetter();
addBrandPage.updateLogoDisplay(letter);
}
}
对LogoAdapter类进行了类似的修改。