Question

我想在我正在开发的viewpager中存储按钮收藏状态，以便用户可以随时回顾他们已经预订为收藏夹的图像。存储按钮状态，但是，一旦我重新打开应用程序，按钮状态就没有改变。是因为活动被破坏了吗？如何在viewpager中存储按钮的状态？

    @Override
        public Object instantiateItem(final ViewGroup container, final int position) {
            showProgress();

            imageView = (ImageView) findViewById(R.id.btn_favourite);
            imageView.setColorFilter(Color.argb(255, 192, 192, 192));

            imageView.setOnClickListener(new View.OnClickListener() {
                Boolean stateBtn= sharedPreference.getBtnState(context);

                @Override
                public void onClick(View v) {
//                    Boolean stateBtn= sharedPreference.getBtnState(context);
                    if(!stateBtn) {
                        sharedPreference.save(context, mUrl);
                        sharedPreference.saveBtnState(context, stateBtn);
                        Toast.makeText(context,
                                "Added to Favourite!",
                                Toast.LENGTH_SHORT).show();
                        imageView.setColorFilter(Color.argb(255, 249, 0, 0));
                    }
                    else
                    {
                        sharedPreference.saveBtnState(context, stateBtn);
                        imageView.setColorFilter(Color.argb(255, 192, 192, 192));
                    }
                }
            });

            View photoRow = inflater.inflate(R.layout.item_image, container,
                    false);

            ImageView image = (ImageView) photoRow.findViewById(R.id.img_flickr);

           // added imageloader for better performance
            StaggeredDemoApplication.getImageLoader().get(imageArrayList[position],
                    ImageLoader.getImageListener(image, R.drawable.bg_no_image, android.R.drawable.ic_dialog_alert), container.getWidth(), 0);
            ((ViewPager) container).addView(photoRow);
            stopProgress();

            return photoRow;

        }

以下是共享偏好的代码

public class SharedPreference {

public static final String PREFS_NAME = "AOP_PREFS";
public static final String PREFS_STATE="AOP_BTN";
public static final String PREFS_KEY = "AOP_PREFS_String";
public static final String PREF_BTN_KEY = "AOP_PREF_BTN";

public SharedPreference() {
    super();
}

public void save(Context context, String text) {
    SharedPreferences settings;
    Editor editor;

    //settings = PreferenceManager.getDefaultSharedPreferences(context);
    settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE); //1
    editor = settings.edit(); //2
    editor.putString(PREFS_KEY, text); //3
    editor.commit(); //4

}

public String getValue(Context context) {
    SharedPreferences settings;
    String text;

    //settings = PreferenceManager.getDefaultSharedPreferences(context);
    settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    text = settings.getString(PREFS_KEY, null);

    return text;
}

public void clearSharedPreference(Context context) {
    SharedPreferences settings;
    Editor editor;

    //settings = PreferenceManager.getDefaultSharedPreferences(context);
    settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    editor = settings.edit();

    editor.clear();
    editor.commit();
}

public void removeValue(Context context) {
    SharedPreferences settings;
    Editor editor;

    settings = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
    editor = settings.edit();

    editor.remove(PREFS_KEY);
    editor.commit();
}

public void saveBtnState(Context context, Boolean stateBtn) {

    SharedPreferences settings;
    Editor editor;

    //settings = PreferenceManager.getDefaultSharedPreferences(context);
    settings = context.getSharedPreferences(PREFS_STATE, Context.MODE_PRIVATE); //1
    editor = settings.edit(); //2
    editor.putBoolean(PREF_BTN_KEY, stateBtn);//added state for button
    editor.commit(); //4

}

 public boolean getBtnState(Context context)
{
    SharedPreferences prefs =  context.getSharedPreferences(PREFS_STATE, Context.MODE_PRIVATE);
    boolean switchState = prefs.getBoolean(PREF_BTN_KEY, false);
    return switchState;
}
}

Answer 1

不，因为你打错了偏好。您必须使用PREFS_STATE代替PREFS_NAME，并使用PREF_BTN_KEY代替PREFS_NAME。这是因为在保存按钮状态时，您使用了键PREFS_STATE的首选项，并将布尔值设置为PREF_BTN_KEY。

public boolean getBtnState(Context context)
{
    SharedPreferences prefs =  context.getSharedPreferences(PREFS_STATE, Context.MODE_PRIVATE);
    boolean switchState = prefs.getBoolean(PREF_BTN_KEY, false);
    return switchState;
}

Answer 2

更改 getBtnState 方法

public boolean getBtnState(Context context)
{
   SharedPreferences prefs =  context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
   boolean switchState = prefs.getBoolean(PREF_BTN_KEY, false);
   return switchState;
}

Android按钮状态未存储在viewpager中

2 个答案: