重新启动Android后自定义小部件中的Android持久可检查菜单

Question

您好，我设计了一个自定义工具栏，使用来自

的提示，用弹出菜单替换操作栏

how to save menuitem visibility state through sharedpreferences?

和

Checkbox item state on menu android

和

http://developer.android.com/guide/topics/ui/menus.html#checkable

最有效的方法是将状态存储在共享首选项中，就像在 stackoverflow 答案中一样。

我的问题是：即使在重新启动我的 android 后，如何保持选中的选项处于选中状态？

Answer 1

一种方法是在.commit() 之前调用.clear() 方法。

另一个是检索共享首选项中最后存储的值。但是，要做到这一点，必须了解活动的生命周期：

存储用户偏好的勾选状态后，如下： 声明变量

/**Checkable Login Persist Shared Prefs Declarations Start*/
private static final String PREFS_NAME = "IsCheckedState";
String string;
SharedPreferences.Editor editor;
/**Checkable Login Persist Shared Prefs Declarations End*/

设置布局后，将字符串（无论您的情况是布尔值还是整数）变量分配给共享首选项。

protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
     /**
      Persistent Checkable Menu Start
      **/
     SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
     string = settings.getString("preference", string);
     //Log.e("User Subscription", string);
     /**
      Persistent Checkable Menu End
      **/}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    super.onPrepareOptionsMenu(menu);
    SharedPreferences settings = this.getSharedPreferences(PREFS_NAME, 0);
    string = settings.getString("preference", string);
    if (string.equals("Vibrate")) {
        menu.findItem(R.id.start_action).setChecked(true);
        Log.e("Vibrate", string);
    }
    else if (string.equals("Disable")){
        menu.findItem(R.id.my_cancel_action).setChecked(true);
        Log.e("Disable", string);
    }
    return true;
}
// Menu options to set and cancel the alarm.
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    /*persistent checkable item logic start*/
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    editor = settings.edit();
    string = settings.getString("preference", string);
     /*persistent checkable item logic end*/
    int id = item.getItemId();
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    switch (id) {

        // When the user clicks START ALARM, set the alarm.
        case R.id.start_action:
            alarm.setAlarm();
            item.setChecked(true);
            string= "Vibrate";
            editor.putString("preference", string);
            editor.commit();
            // invalidateOptionsMenu();
            return true;
        // When the user clicks CANCEL ALARM, cancel the alarm.
        case R.id.my_cancel_action:
            alarm.cancelAlarm(this, 1);
            item.setChecked(true);
            string="Disable";
            editor.putString("preference", "Disable");
            editor.commit();
            //invalidateOptionsMenu();
            return true;
    }
    return super.onOptionsItemSelected(item);
}

当应用程序暂停、停止、恢复可见（启动）时，您必须从共享首选项中检索先前存储的字符串。因此，除了上面的代码，您还需要添加以下内容：

}
@Override
public void onResume() {
    super.onResume();
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    string = settings.getString("preference", string);
}

@Override
protected void onStart() {
    super.onStart();
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    string = settings.getString("preference", string);
}

@Override
protected void onRestart() {
    super.onRestart();
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    string = settings.getString("preference", string);
}


@Override
protected void onPause() {
    super.onPause();
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    string = settings.getString("preference", string);
}
@Override
protected void onStop() {
    super.onStop();
    SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
    string = settings.getString("preference", string);
}

也就是说，如果您真的希望始终存储选中的选项。