我有两个 Activity MainActivity 和 SecondActivity
Activity MainActivity.java 中的代码
public class MainActivity extends FragmentActivity implements OnMarkerClickListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().requestFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main_screen);
databaseobj = new AppDatabase(MainActivity.this, null);
listview = (ListView) findViewById(R.id.store_listview);
noSavedMsg = (TextView) findViewById(R.id.no_msg);
..
..
..//Other code logic
..
}
@Override
protected void onResume() {
if (databaseobj.GetAll() != -1) { //NULL POINTER EXCEPTION
listview.setVisibility(View.GONE); //NULL POINTER EXCEPTION
noSavedMsg.setVisibility(View.VISIBLE); //NULL POINTER EXCEPTION
}
super.onResume();
}
}
从另一个 Activity 返回后,我收到空指针异常;
MainActivity -> SecondActivity 的新 Intent
SecondActivity->finish() 然后 MainActivity-> onResume() 空指针异常
请帮忙!
最佳答案
您的TextView
名称是noSavedMsg
,但您正在尝试设置名为NoSavedMsg
的 View 的可见性...这两个不一样。
更改此行...
NoSavedMsg.setVisibility(View.VISIBLE);
到...
noSavedMsg.setVisibility(View.VISIBLE);
关于java - onResume 中的 NullPointerException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22281144/