Android 如何在SharedReferences RecyclerView中保存特定复选框项并检索它们
我在Android 如何在SharedReferences RecyclerView中保存特定复选框项并检索它们,android,sharedpreferences,Android,Sharedpreferences,我在RecyclerView中有一些数据,每个项目中都有一个复选框按钮。我使用SharedReference保存特定的检查数据并检索它们 例如:如果我只勾选了数据“A”,它将只保存数据“A”。我写了一些代码来实现这一点,但每次我检查特定数据时,它都会检查所有数据,每次我检查特定数据时,它都会检查所有数据 我已经尝试了很多天来解决这个问题,但直到现在仍然坚持 MainActivity.java public class HomeActivity extends AppCompatActivity
RecyclerView
中有一些数据,每个项目中都有一个复选框按钮。我使用SharedReference
保存特定的检查数据并检索它们
例如:如果我只勾选了数据“A”,它将只保存数据“A”。我写了一些代码来实现这一点,但每次我检查特定数据时,它都会检查所有数据,每次我检查特定数据时,它都会检查所有数据
我已经尝试了很多天来解决这个问题,但直到现在仍然坚持
MainActivity.java
public class HomeActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private List<Story> storyList = new ArrayList<>();
AppPreferences appPreferences;
private Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
recyclerView = findViewById(R.id.recycler_view);
SharedPreferences sharedPreferences = getApplicationContext().getSharedPreferences("MyPref", 0);
PreferenceManager preferenceManager = new PreferenceManager(sharedPreferences);
appPreferences = new AppPreferences(preferenceManager);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
recyclerView.setAdapter(new AdapterHome(storyList, this, appPreferences));
setUpData();
}
private void setUpData() {
for (int i = 0; i < 10; i++) {
Story story = new Story();
story.setIdStory(String.valueOf(i));
story.setIsLiked(0);
story.setTitle("Sample " + i);
storyList.add(story);
}
} }
public class AdapterHome extends RecyclerView.Adapter<AdapterHome.ViewHolder> {
public static final String PREFS_NAME = "PRODUCT_APP";
public static final String FAVORITES = "Product_Favorite";
private List<Story> storyList;
private List<Story> favorites;
private Context context;
private int changedItemPosition;
private boolean isLiked;
private AppPreferences appPreferences;
private SharedPreferences preferences;
private CheckBox checkBox;
Boolean checked = false;
Boolean[] checkedStatus;
public AdapterHome(List<Story> storyList, Context context, AppPreferences appPreferences) {
this.storyList = storyList;
this.context = context;
this.appPreferences = appPreferences;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
return new ViewHolder(LayoutInflater.from(context).inflate(R.layout.item_story_home, parent, false));
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
holder.setViewData(storyList.get(position), holder.getAdapterPosition());
}
@Override
public int getItemCount() {
return storyList.size();
}
//The problem lays here
public void putHeart(boolean isChecked, String key) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("MyPref", isChecked);
editor.commit();
}
public boolean getHeart(String key) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
Boolean isChecked = sharedPreferences.getBoolean("MyPref", false);
return isChecked;
}
//ViewHolder
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView textView;
private CheckBox likeCheckBox;
public ViewHolder(View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.text_view);
likeCheckBox = itemView.findViewById(R.id.like_button_cb);
}
public void setViewData(final Story story, final int adapterPosition) {
textView.setText(story.getTitle());
if (story.getIsLiked() == 1) {
likeCheckBox.setChecked(true);
}
else {
likeCheckBox.setChecked(false);
}
// The problem lays here
boolean isChecked = getHeart("MyPref");
likeCheckBox.setChecked(isChecked);
likeCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
changedItemPosition = adapterPosition;
if (buttonView.isPressed()) {
if (isChecked) {
isLiked = true;
updateLikes();
appPreferences.saveFavouriteCard(story);
putHeart(isChecked,"isChecked"); // The problem lays here
Toast.makeText(context, "Saved", Toast.LENGTH_SHORT).show();
}
else {
isLiked = false;
updateLikes();
appPreferences.deleteCard(story.getIdStory());
putHeart(isChecked,"isChecked"); // The problem lays here
Toast.makeText(context, "Removed", Toast.LENGTH_SHORT).show();
}
}
}
});
} //setviewdata
public void updateLikes() {
if (isLiked && storyList.get(changedItemPosition).getIsLiked() == 0) { //jika dilakukan like (pada posisi hati kosong) di halaman home
storyList.get(changedItemPosition).setIsLiked(1); //maka jadikan hati berwarna merah di halaman favourite list
notifyItemChanged(changedItemPosition, ACTION_LIKE_IMAGE_CLICKED);
}
else if (!isLiked && storyList.get(changedItemPosition).getIsLiked() == 1) { //jika like dicabut (pada posisi hati yang sedang merah) di halaman home
storyList.get(changedItemPosition).setIsLiked(0); //maka cabut juga warna merah di halaman favourite list
notifyItemChanged(changedItemPosition, ACTION_LIKE_IMAGE_CLICKED);
}
} //updateLikes
} //viewholder } //AdapterHome
Story.java
public class Story {
public Story(){}
private String idStory;
private String title;
private int isLiked;
private int ambilID;
public String getIdStory() {
return idStory;
}
public void setIdStory(String isStory) {
this.idStory = isStory;
}
public int ambilIdStory() {
return ambilID;
}
public void putIdStory(int isStory) {
this.ambilID = isStory;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public int getIsLiked() {
return isLiked;
}
public void setIsLiked(int isLiked) {
this.isLiked = isLiked;
}
@Override
public String toString() {
return GsonUtils.convertToJSON(this);
}
}
更新代码[工作]
最后,问题已经解决了。它可以用每个项目的唯一标识符来解决。因此,即使故事顺序更改,也会保存故事的已检查状态
public void putHeart(boolean isChecked, int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
Story story = storyList.get(position);
editor.putBoolean(story.getIdStory(), isChecked);
editor.commit();
}
public boolean getHeart(int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
Story story = storyList.get(position);
boolean isChecked = sharedPreferences.getBoolean(story.getIdStory(), false);
return isChecked;
}
由于数据总是生成的,所以可以使用列表中的位置作为首选项中布尔值的键
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean(String.valueOf(position), isChecked);
editor.commit();
然后:
SharedPreferences.Editor editor = sharedPreferences.edit();
boolean b = editor.getBoolean(String.valueOf(position), false);
更新
boolean isChecked = getHeart(getAdapterPosition());
likeCheckBox.setChecked(isChecked);
likeCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
changedItemPosition = getAdapterPosition();
if (buttonView.isPressed()) {
if (isChecked) {
isLiked = true;
updateLikes();
appPreferences.saveFavouriteCard(story);
putHeart(isChecked, getAdapterPosition()); // The problem lays here
Toast.makeText(context, "Saved", Toast.LENGTH_SHORT).show();
}
else {
isLiked = false;
updateLikes();
appPreferences.deleteCard(story.getIdStory());
putHeart(isChecked,getAdapterPosition()); // The problem lays here
Toast.makeText(context, "Removed", Toast.LENGTH_SHORT).show();
}
}
}
});
保存和恢复状态
public void putHeart(boolean isChecked, int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean(String.valueOf(position), isChecked);
editor.commit();
}
public boolean getHeart(int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
Boolean isChecked = sharedPreferences.getBoolean(String.valueOf(position), false);
return isChecked;
}
您应该为您的
故事
生成唯一标识符。如身份证、姓名等
// put isChecked to shared prefs
Story story = storyList.get(pos);
editor.putBoolean(Integer.toString(story.getId()), isChecked);
这样,即使故事顺序更改,也会保存故事的已检查状态。无法解析符号“位置”。这就是问题所在。我已经尝试过很多次了,这是在onCheckedChanged方法中的结果,您可以使用getAdapterPosition()检索位置;并将其传递给保存状态方法。你太棒了。。你的代码是工作。谢谢你,伙计。我从没想过要这么做。可怜的我。。。hiksBut问题是当故事顺序改变时,它可以处理特定的项目。你能帮帮我吗?是的,我以前就知道。但是,我该怎么做呢?我试了很多次,但都失败了。你是说生成一个id?是的。生成Id,将Id放入
SharedReferences
并获取Id。我已经更新了我的答案,向您展示了如何生成唯一的Id。。这个问题把我带到了这里。故事
的唯一标识符。如id、名称等已生成。但仍然不起作用。你能给我写完整的代码吗?
public void putHeart(boolean isChecked, int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
Story story = storyList.get(position);
editor.putBoolean(story.getIdStory(), isChecked);
editor.commit();
}
public boolean getHeart(int position) {
SharedPreferences sharedPreferences = context.getSharedPreferences("MyPref", Activity.MODE_PRIVATE);
Story story = storyList.get(position);
boolean isChecked = sharedPreferences.getBoolean(story.getIdStory(), false);
return isChecked;
}
// get isChecked from shared prefs
Story story = storyList.get(pos);
boolean isChecked = boolean b = editor.getBoolean(Integer.toString(story.getId()), false);
// generate id
// when you create a Story
int lastIdGenerated = editor.getInt("LAST_ID_GENERATED", 1);
int newId = lastIdGenerated + 1;
editor.putInt("LAST_ID_GENERATED", newId);
Story newStory = new Story();
newStory.setId(newId);