我面临这个问题,我有MainActivity和SettingsPreference,所以当我从设置返回到MainActivity时,我想在MainActivity上重新加载适配器,我使用onResume(),当我单击ActionBar后退按钮时,它工作得很好,但是当我尝试时它位于硬件后退按钮上,它从未被调用,我发现系统调用 onPostResume() 而不是 onResume(),因此尝试使用它,但更改从未被应用
this is the SettingsActivity i'm using
当按下 ActionBar 后退按钮时,此代码起作用
@Override
protected void onResume() {
super.onResume();
dataFromSharedPrefrence = getSettingsSharedPreferences();
adapterExample.notifyDataSetChanged();
}
按下硬件后退按钮时系统会调用 onPostResume(),但更改从未应用
@Override
protected void onPostResume() {
super.onPostResume();
dataFromSharedPrefrence = getSettingsSharedPreferences();
adapterExample.notifyDataSetChanged();
}
这是设置 Activity
public class SettingsActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings_activity);
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.settings, new SettingsFragment())
.commit();
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
public static class SettingsFragment extends PreferenceFragmentCompat {
@Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.root_preferences, rootKey);
}
}
当我重写生命周期方法时,我发现了这种差异
- 按下 ActionBar 按钮时,这是输出
2020-05-05 06:00:44.899 23467-23467/com.example.test E/MainActivity: onDestroy
2020-05-05 06:00:44.907 23467-23467/com.example.test E/MainActivity: onDetachedFromWindow
2020-05-05 06:00:44.964 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:44.990 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:45.009 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:45.015 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:45.037 23467-23467/com.example.test E/MainActivity: onContentChanged
2020-05-05 06:00:45.048 23467-23467/com.example.test E/MainActivity: onStart
2020-05-05 06:00:45.051 23467-23467/com.example.test E/MainActivity: onPostCreate
2020-05-05 06:00:45.053 23467-23467/com.example.test E/MainActivity: onResume
2020-05-05 06:00:45.056 23467-23467/com.example.test E/MainActivity: onPostResume
2020-05-05 06:00:45.078 23467-23467/com.example.test E/MainActivity: onAttachedToWindow
2020-05-05 06:00:45.141 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:45.188 23467-23467/com.example.test E/MainActivity: onCreateView
2020-05-05 06:00:45.223 23467-23467/com.example.test E/MainActivity: onCreateView
- 当按下硬件后退按钮时,这是输出
2020-05-05 06:01:21.732 23467-23467/com.example.test E/MainActivity: onRestart
2020-05-05 06:01:21.734 23467-23467/com.example.test E/MainActivity: onStart
2020-05-05 06:01:21.738 23467-23467/com.example.test E/MainActivity: onResume
2020-05-05 06:01:21.739 23467-23467/com.example.test E/MainActivity: onPostResume
最佳答案
试试这个:
不要使用onResume()
,而是尝试onStart()
:
@Override
protected void onStart() {
super.onStart();
dataFromSharedPrefrence = getSettingsSharedPreferences();
adapterExample.notifyDataSetChanged();
}
关于java - 在Android上单击手机硬件后退按钮时从未调用过onResume?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61603140/