我在 fragment 中有一个 recyclerview，当用户点击它时，单元格的内容会发生变化。
用户点击该项目后，内容发生变化。但是，这只适用于第一次，但当我单击不同的行时，它们并没有改变。现在，数据源数据正在发生变化，因为如果我退出 Activity 并返回，则会显示正确的数据。为什么会这样。
我真的不明白的是，我调试的时候，我每次都通过adatper，数据是正确的，它告诉我它正在执行改变单元格外观的代码，但它并没有'实际上改变了!
这是我的 fragment :
public class AerobicFragment extends Fragment {
private static final String TAG = "999.AerobicFragment";
public static final String JSON_STRING_EXERCISES = "999.JSON_STRING_EXERCISES";
private RecyclerView exerciseRecyclerView;
private ExerciseAdapter exerciseAdapter;
public ArrayList<Exercise> exerciseList;
public static final int REQUEST_CODE_ADD_EXERCISE = 394;
private boolean aerobicExerciseSetUp;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_aerobic, container, false);
exerciseList = new ArrayList<>();
exerciseList = SharedPreferencesManager.getAerobicExercisesList(getContext());
Log.d(TAG, "Aerobic Exercise List Size: " + exerciseList.size());
aerobicExerciseSetUp = SharedPreferencesManager.getAerobicExercisesCreated(getContext());
if(!aerobicExerciseSetUp){
showDialog();
}
exerciseRecyclerView = (RecyclerView) v.findViewById(R.id.exercise_recycler_view);
exerciseAdapter = new ExerciseAdapter(exerciseList);
exerciseRecyclerView.setAdapter(exerciseAdapter);
exerciseRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
exerciseAdapter.setOnItemClickListener(new ExerciseAdapter.ClickListener() {
@Override
public void onItemClick(final int position, View v) {
Log.d(TAG, "onItemClick pos = " + position);
int timesLeftInt = Integer.parseInt(exerciseList.get(position).getTimesPerWeek()) - exerciseList.get(position).getTimesDoneThisWeek();
if(timesLeftInt != 0){
AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
builder.setMessage("Did you do your " + exerciseList.get(position).getNameOfExercise() +
" for " + exerciseList.get(position).getDurationOfExercise() + "?")
.setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
int newTimesDoneThisWeek = exerciseList.get(position).getTimesDoneThisWeek();
newTimesDoneThisWeek++;
exerciseList.get(position).setTimesDoneThisWeek(newTimesDoneThisWeek);
SharedPreferencesManager.setAerobicExercisesList(getContext(), exerciseList);
exerciseAdapter.notifyDataSetChanged();
}
})
.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
// User cancelled the dialog
}
});
// Create the AlertDialog object and return it
builder.create();
builder.show();
}
}
});
return v;
}
private void showDialog() {
if(!aerobicExerciseSetUp){
AlertDialog alertDialog = new AlertDialog.Builder(getContext()).create();
alertDialog.setTitle("No aerobic exercises are set up yet");
alertDialog.setMessage("Do you wish to add an aerobic exercise now?");
alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "Yes please",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
Intent intent = new Intent(getContext(), TypeOfAerobicExerciseActivity.class);
startActivityForResult(intent, REQUEST_CODE_ADD_EXERCISE);
}
});
alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE, "Not now",
new DialogInterface.OnClickListener(){
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.setCancelable(true);
alertDialog.show();
}
}
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
}
else {
}
}
public static AerobicFragment newInstance(String text) {
AerobicFragment f = new AerobicFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
这是适配器:
public class ExerciseAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final String TAG = "999.ExerciseAdapter";
private static ClickListener clickListener;
public ImageView exerciseItemIcon;
public TextView exerciseNameTextView;
public TextView exerciseDurationTextView;
public TextView exerciseTimesRemainingTextView;
public TextView exerciseTimesRemainingCONSTANTTextView;
ArrayList<Exercise> exerciseArrayList = new ArrayList<>();
public ExerciseAdapter(ArrayList<Exercise> exerciseArrayList) {
this.exerciseArrayList = exerciseArrayList;
}
public interface ClickListener {
void onItemClick(int position, View v);
}
class ExerciseViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
public ExerciseViewHolder(View view) {
super(view);
view.setOnClickListener(this);
exerciseNameTextView = (TextView)view.findViewById(R.id.exercise_name_textView);
exerciseDurationTextView = (TextView)view.findViewById(R.id.exercise_duration_textview);
exerciseTimesRemainingTextView = (TextView)view.findViewById(R.id.exercise_times_remaining_textview);
exerciseItemIcon = (ImageView)view.findViewById(R.id.exercise_item_icon);
exerciseTimesRemainingCONSTANTTextView = (TextView)view.findViewById(R.id.timesRemainingConstantTextView);
}
@Override
public void onClick(View v) {
clickListener.onItemClick(getAdapterPosition(), v);
}
}
public void setOnItemClickListener(ClickListener clickListener) {
ExerciseAdapter.clickListener = clickListener;
}
@Override
public int getItemViewType(int position) {
// Just as an example, return 0 or 2 depending on positio
n
// Note that unlike in ListView adapters, types don't have to be contiguous
// return position % 2 * 2;
return position;
}
@Override
public int getItemCount() {
return exerciseArrayList.size();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.exercise_item_row, parent, false);
return new ExerciseViewHolder(itemView);
}
@Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
ExerciseViewHolder exerciseViewHolder = (ExerciseViewHolder) holder;
exerciseNameTextView.setText(exerciseArrayList.get(position).getNameOfExercise());
exerciseDurationTextView.setText(exerciseArrayList.get(position).getDurationOfExercise());
int timesRemainingThisWeek = Integer.parseInt(exerciseArrayList.get(position).getTimesPerWeek())
- exerciseArrayList.get(position).getTimesDoneThisWeek();
Log.d(TAG, "Times remaining: " + timesRemainingThisWeek);
if (timesRemainingThisWeek != 0){
exerciseTimesRemainingTextView.setText("" + timesRemainingThisWeek);
exerciseTimesRemainingCONSTANTTextView.setVisibility(View.VISIBLE);
}else{
exerciseTimesRemainingTextView.setText("DONE");
exerciseTimesRemainingCONSTANTTextView.setVisibility(View.INVISIBLE);
}
exerciseItemIcon.setImageResource(exerciseArrayList.get(position).getExerciseIcon());
}
}
这是我的项目行的 xml:
<?xml version="1.0"
encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/card_view_exercise"
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_margin="10dp"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp"
android:padding="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
>
<ImageView
android:layout_width="80dp"
android:layout_height="80dp"
android:id="@+id/exercise_item_icon"
android:src="@drawable/exercise_swimming_icon"
android:padding="10dp"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="vertical"
android:gravity="center_vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Swimming"
android:gravity="center_vertical"
android:id="@+id/exercise_name_textView"
android:textColor="@color/colorPrimary"
android:textSize="18sp"
android:padding="2dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="20 minutes"
android:gravity="center_vertical"
android:id="@+id/exercise_duration_textview"
android:textColor="@color/colorPrimary"
android:textSize="14sp"
android:padding="2dp"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:gravity="center_vertical"
android:paddingRight="5dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="3"
android:gravity="right"
android:id="@+id/exercise_times_remaining_textview"
android:textColor="@color/colorPrimary"
android:textSize="30sp"
android:padding="2dp"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="time(s) remaining"
android:gravity="right"
android:textColor="@color/colorPrimary"
android:id="@+id/timesRemainingConstantTextView"
android:textSize="14sp"
android:padding="2dp"/>
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
非常感谢
最佳答案
对于列表中的特定适配器位置使用
notifyItemChanged (int position)
方法。
编辑:你能用下面的代码替换你的 onBindViewHolder 方法并尝试使用它吗？
@Override
public void onBindViewHolder(final ExerciseViewHolder holder, final int position) {
holder.exerciseNameTextView.setText(exerciseArrayList.get(position).getNameOfExercise());
holder.exerciseDurationTextView.setText(exerciseArrayList.get(position).getDurationOfExercise());
int timesRemainingThisWeek = Integer.parseInt(exerciseArrayList.get(position).getTimesPerWeek())
- exerciseArrayList.get(position).getTimesDoneThisWeek();
Log.d(TAG, "Times remaining: " + timesRemainingThisWeek);
if (timesRemainingThisWeek != 0){
holder.exerciseTimesRemainingTextView.setText("" + timesRemainingThisWeek);
holder.exerciseTimesRemainingCONSTANTTextView.setVisibility(View.VISIBLE);
}else{
holder.exerciseTimesRemainingTextView.setText("DONE");
holder.exerciseTimesRemainingCONSTANTTextView.setVisibility(View.INVISIBLE);
}
holder.exerciseItemIcon.setImageResource(exerciseArrayList.get(position).getExerciseIcon());
}
编辑 2:您还需要修复父类(super class)定义。将下面的代码用于适配器。
public class ExerciseAdapter extends RecyclerView.Adapter<ExerciseAdapter.ExerciseViewHolder> {
private static final String TAG = "999.ExerciseAdapter";
private static ClickListener clickListener;
public ImageView exerciseItemIcon;
public TextView exerciseNameTextView;
public TextView exerciseDurationTextView;
public TextView exerciseTimesRemainingTextView;
public TextView exerciseTimesRemainingCONSTANTTextView;
ArrayList<Exercise> exerciseArrayList = new ArrayList<>();
public ExerciseAdapter(ArrayList<Exercise> exerciseArrayList) {
this.exerciseArrayList = exerciseArrayList;
}
public interface ClickListener {
void onItemClick(int position, View v);
}
class ExerciseViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
public ExerciseViewHolder(View view) {
super(view);
view.setOnClickListener(this);
exerciseNameTextView = (TextView)view.findViewById(R.id.exercise_name_textView);
exerciseDurationTextView = (TextView)view.findViewById(R.id.exercise_duration_textview);
exerciseTimesRemainingTextView = (TextView)view.findViewById(R.id.exercise_times_remaining_textview);
exerciseItemIcon = (ImageView)view.findViewById(R.id.exercise_item_icon);
exerciseTimesRemainingCONSTANTTextView = (TextView)view.findViewById(R.id.timesRemainingConstantTextView);
}
@Override
public void onClick(View v) {
clickListener.onItemClick(getAdapterPosition(), v);
}
}
public void setOnItemClickListener(ClickListener clickListener) {
ExerciseAdapter.clickListener = clickListener;
}
@Override
public int getItemViewType(int position) {
// Just as an example, return 0 or 2 depending on position
// Note that unlike in ListView adapters, types don't have to be contiguous
// return position % 2 * 2;
return position;
}
@Override
public int getItemCount() {
return exerciseArrayList.size();
}
@Override
public ExerciseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.exercise_item_row, parent, false);
return new ExerciseViewHolder(itemView);
}
@Override
public void onBindViewHolder(final ExerciseViewHolder holder, final int position) {
holder.exerciseNameTextView.setText(exerciseArrayList.get(position).getNameOfExercise());
holder.exerciseDurationTextView.setText(exerciseArrayList.get(position).getDurationOfExercise());
int timesRemainingThisWeek = Integer.parseInt(exerciseArrayList.get(position).getTimesPerWeek())
- exerciseArrayList.get(position).getTimesDoneThisWeek();
Log.d(TAG, "Times remaining: " + timesRemainingThisWeek);
if (timesRemainingThisWeek != 0){
holder.exerciseTimesRemainingTextView.setText("" + timesRemainingThisWeek);
holder.exerciseTimesRemainingCONSTANTTextView.setVisibility(View.VISIBLE);
}else{
holder.exerciseTimesRemainingTextView.setText("DONE");
holder.exerciseTimesRemainingCONSTANTTextView.setVisibility(View.INVISIBLE);
}
holder.exerciseItemIcon.setImageResource(exerciseArrayList.get(position).getExerciseIcon());
}
关于android - notifyDataSetChanged() recyclerview，只有第一个单元格点击更改，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47370560/