如何将 SharedPreferences 数据从 settingActivity 传递到 MainAdapter？

Question

我创建了一个购物车应用，它有一个菜单项。然后它有另一个 activity 叫做 "SettingActivity"，因为这个 settingActivity 将有一个 TextView 来显示 "Primary language, secondary language and both language"。

我在 SettingActivity 中获取了 SharedPreferences 数据。如何将这些数据传递给 MainAdapter？

因为当我在 SettingActivity 中点击次要语言时，菜单将更改为次要语言或显示两种语言。

那么，如何获取MainAdapter中SettingActivity的SharedPreference数据呢？

设置活动：

public class SettingActivity extends AppCompatActivity {
LinearLayout languageModeLinearLayout;
TextView languageModeTextView;
SharedPreferences settingPreferences;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_setting);
    languageModeLinearLayout = findViewById(R.id.setting_language_mode_linearLayout);
    languageModeTextView = findViewById(R.id.setting_language_mode_textView);
    settingPreferences = getSharedPreferences("setting", MODE_PRIVATE);

    updateUI();

    languageModeLinearLayout.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final String[] language = getResources().getStringArray(R.array.setting_language_mode);
            AlertDialog.Builder languageMode = new AlertDialog.Builder(v.getContext());
            languageMode.setTitle("Select Language Mode");
           languageMode.setItems(language, new DialogInterface.OnClickListener() {
               @Override
               public void onClick(DialogInterface dialog, int position) {
                   SharedPreferences.Editor editor = settingPreferences.edit();
                   editor.putInt("language", position);
                   editor.apply();
                   updateUI();
               }
           });

           languageMode.create().show();
        }
    });


}

private String getLanguage(){
    String[] language = getResources().getStringArray(R.array.setting_language_mode);
    int position;
 position  = settingPreferences.getInt("language", 0);

 return language[position];
}

private void updateUI(){
    languageModeTextView.setText(getLanguage());
}

主适配器：

public class MainAdapter extends ArrayAdapter<MenuItem> implements Serializable {
private TextView mCartCounterTextView;

public MainAdapter(Context context, List<MenuItem> menuItems) {
    super(context, 0, menuItems);
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    View itemView = convertView;
    final ViewHolder viewHolder;

    if (itemView == null) {
        itemView = LayoutInflater.from(getContext()).inflate(R.layout.item_main, parent, false);
        viewHolder = new ViewHolder(itemView);
        itemView.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) itemView.getTag();
    }

    final MenuItem currentMenuItem = getItem(position);
    viewHolder.nameTextView.setText(currentMenuItem.getPrimaryName());
    viewHolder.nameTextView.setText(currentMenuItem.getSecondaryName());

    viewHolder.addToCartButton.setText(getFormattedPriceTextToButton(currentMenuItem));
    viewHolder.addToCartButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Main.getAddedItems().add(currentMenuItem);
            Toast.makeText(v.getContext(), "Item had added to cart", Toast.LENGTH_SHORT).show();

            mCartCounterTextView.setText(String.valueOf(Main.getAddedItems().size()));
            mCartCounterTextView.setVisibility(View.VISIBLE);
        }
    });
    return itemView;
}

private String getFormattedPriceTextToButton(MenuItem currentMenuItem) {
    return "+ $" + currentMenuItem.getPrice();
}

private class ViewHolder {
    TextView nameTextView;
    TextView priceTextView;
    Button addToCartButton;

    public ViewHolder(View itemView) {
        nameTextView = itemView.findViewById(R.id.main_name_textView);
        priceTextView = itemView.findViewById(R.id.main_price_textView);
        addToCartButton = itemView.findViewById(R.id.main_add_to_cart_button);
    }
}

public void setData(TextView cartCounter){
    mCartCounterTextView = cartCounter;
}

private void getSharedPreferencesLanguage(){
  //  SharedPreferences.Editor editor = getContext().getSharedPreferences("setting", MODE_PRIVATE).edit();
    SharedPreferences language = getContext().getSharedPreferences("setting", MODE_PRIVATE);
}

菜单项：

public class MenuItem {
private String mPrimaryName;
private String mSecondaryName;
private double mPrice;

public MenuItem(String primaryName, String secondaryName, double price){
    mPrimaryName = primaryName;
    mSecondaryName = secondaryName;
    mPrice = price;
}

public String getPrimaryName(){
    return mPrimaryName;
}
public String getSecondaryName(){
    return mSecondaryName;
}
public double getPrice(){
    return mPrice;
}

Answer 1

我认为你在

上做得很好

SharedPreferences language = getContext().getSharedPreferences("setting", MODE_PRIVATE);

但是现在如果你想获取数据（在这种情况下是语言 int），你只需执行以下操作：

int lang_int = language.getInt("language",0);

Answer 2

只需将上下文传递给函数并从 sharedpref 获取值

    public static String getLan(Context cont) {
SharedPreferences settingPreferences=settingPreferences =cont.getSharedPreferences("setting", MODE_PRIVATE);
String[] language = getResources().getStringArray(R.array.setting_language_mode);
int posi =settingPreferences.getInt("language",0);
return language[pos];
}

如何将 SharedPreferences 数据从 settingActivity 传递到 MainAdapter？

How to pass the SharedPreferences data from the settingActivity to the MainAdapter?

java

android

sharedpreferences