I am trying to understand ViewModel and LiveData.
In MainActivity, I am observing LiveData In MyTask, I am setting data on the LiveData, that should be displayed in the activity.
Problem is data set in MyTask is not getting updated on the UI.
MainActivity
public class MainActivity extends AppCompatActivity {
private MyViewModel viewModel;
private TextView tv2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv2 = findViewById(R.id.textView2);
viewModel = ViewModelProviders.of(this).get(MyViewModel.class);
findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
viewModel.setNameData("Button clicked");
new MyTask(getApplication()).execute();
}
});
viewModel.getNameData().observe(this, new Observer() {
@Override
public void onChanged(@Nullable String s) {
tv2.setText(s);
}
});
}
}
ViewModel class
public class MyViewModel extends AndroidViewModel {
private MutableLiveData nameData = new MutableLiveData<>();
public MutableLiveData getNameData() {
return nameData;
}
public void setNameData(String name) {
nameData.postValue(name);
}
public MyViewModel(@NonNull Application application) {
super(application);
}
}
MyTask class
public class MyTask extends AsyncTask {
private MyViewModel viewModel;
public MyTask(Application application){
viewModel = new MyViewModel(application);
}
@Override
protected Void doInBackground(Void... voids) {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
viewModel.setNameData("Done task");
}
}
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