java – 重启Android后自定义小部件中的Android持久性可检查菜单

嗨我设计了一个自定义工具栏,用弹出菜单替换操作栏,使用提示

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,如stackoverflow答案中所示.

我的问题是：即使重新启动我的Android后,如何保持选中的选项？

解决方法:

一种方法是在.commit()之前调用.clear()方法.

另一种方法是检索共享首选项中的最后一个存储值.但是,要做到这一点,必须了解活动的生命周期：

存储已检查的用户首选项状态后,如下所示：
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(无论您的情况可能是boolean或int)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以前存储的字符串.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,如果您确实希望始终存储已选中的选项.

标签：submenu,android,java,checkbox,sharedpreferences
来源： https://codeday.me/bug/20190926/1820230.html