清除并提交更改后刷新首选项活动

Question

我有一个Android PreferencesAcitivty，允许用户将他们的偏好设置重置为默认值。下面的代码工作正常，但在调用editor.clear（）和editor.commit（）之后，Preferences接口不会更新。如何在不重新加载活动或调用onCreate（null）的情况下实现此目的？

public class Preferences extends PreferenceActivity {

    /* Called when someone specifies to view the options menu */
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Set
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.settings, menu);

        // Return
        return true;
    }

    /* Handle options menu selections */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle item selection
        switch (item.getItemId()) {

            case R.id.itemReset:
                // Reset

                // Build
                DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        switch (which){
                        case DialogInterface.BUTTON_POSITIVE:
                            //Yes button clicked
                            SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                            SharedPreferences.Editor editor = preferences.edit();
                            editor.clear();
                            editor.commit();
                            **// TODO: Refresh preferences**
                            break;

                        case DialogInterface.BUTTON_NEGATIVE:
                            //No button clicked
                            break;
                        }
                    }
                };

                // Display
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setMessage("Are you sure you want to reset your settings back to their default options?").setPositiveButton("Yes", dialogClickListener).setNegativeButton("No", dialogClickListener).show();

                // Return
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }

    }

    /* Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        // Super
        super.onCreate(savedInstanceState);

        // Call
        addPreferencesFromResource(R.xml.preferences);
    }
}

Answer 1

你应该看看OnSharedPreferenceChangeListener。

它将为您提供已更改的项目，因此您需要刷新所有项目，但更新已更改的项目。