AlertDialog can't get context in custom adapter

Question

I'm trying to show a AlertDialog when I press a button from a ViewHolder from my adapter. But when I launch this crash with the next message.

E/AndroidRuntime: FATAL EXCEPTION: main Process: cl.abitsoft.todotick, PID: 4172 android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running? at android.view.ViewRootImpl.setView(ViewRootImpl.java:798)

public class CustomAdapter extends ArrayAdapter<RowModel> implements View.OnClickListener {

    private ArrayList<RowModel> DataSet;
    Context context;

    private static class ViewHolder {
        [...]
    }

    public CustomAdapter(ArrayList<RowModel> data, Context context) {
        super(context, R.layout.list_item_main, data);
        this.DataSet = data;
        this.context = context;
    }

    @Override
    public void onClick(View v) {
        int position = (Integer) v.getTag();
        final Object object = getItem(position);

        switch (v.getId()) {
            case R.id.list_delete_button:
                AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
                builder.show();
                break;
        }
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        [...]
    }

}

EDIT: Added MainActivity.class

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener, View.OnClickListener {

    ListView listview;
    private CustomAdapter adapter;

    private Button no, button_accept;
    private EditText edittext_title;
    private Spinner spinner_classes;

    private RowModel rowModel;

    private ArrayList<RowModel> row_models;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(this);

        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        // Se inicializan las variables
        edittext_title = findViewById(R.id.main_edittext_title);
        spinner_classes = findViewById(R.id.main_spinner_classes);
        button_accept = findViewById(R.id.main_button_accept);
        listview = findViewById(R.id.main_listview);
        row_models = new ArrayList<>();
        adapter = new CustomAdapter(row_models, getApplicationContext());
        // AL ListView se le asigna el Adapter con el tipo de objeto que usaremos
        listview.setAdapter(adapter);
        // Creamos un arreglo del tipo String con las variables para el Spinner
        String[] values = {"Pagar", "Cobrar", "Llamar", "Pedir", "Comprar", "Revisar", "Otro"};
        // Agregamos las variables a nuestro Spinner
        spinner_classes.setAdapter(new ArrayAdapter<String>(getApplicationContext(), R.layout.spinner_main, values));
        // Habilitamos el click en nuestro boton
        button_accept.setOnClickListener(this);

        loadRows();
    }
    [...]

score 4 · Accepted Answer · answered Feb 12 '19 at 05:14

4

Pass the context that you have declared globally

AlertDialog.Builder builder = new AlertDialog.Builder(context);

and change the following line to

adapter = new CustomAdapter(row_models, getApplicationContext());

to

adapter = new CustomAdapter(row_models, this);

I hope this will help.

answered Feb 12 '19 at 05:14

hfarhanahmed

184
1
7

yea, that's work perfectly, but can you explain the difference between the `getContext` and `this`? – Christopher Vivar Vivar Feb 12 '19 at 12:54
getApplicationContext() returns the context of the whole application as per its name meanwhile this was referring to your current Activity i.e MainActivity in your case on which you want the dialog to pop up. – hfarhanahmed Feb 12 '19 at 13:15
@ChristopherVivarVivar please mark the answer (correct) so other facing the same issue can easily get to the solution. – hfarhanahmed Feb 13 '19 at 06:26

score 2 · Answer 2 · answered Feb 12 '19 at 05:35

2

Make this 3 changes to resolve your problem,

first pass "this" in CustomAdapter.

adapter = new CustomAdapter(row_models,this);

get Activity in CustomAdapter.

public CustomAdapter(ArrayList<RowModel> data, Activity activity) {
super(context, R.layout.list_item_main, data);
this.DataSet = data;
this.context = context;
}

Create AlertDialoge using "activity".

AlertDialog.Builder builder = new AlertDialog.Builder(activity);

answered Feb 12 '19 at 05:35

Mayur Dabhi

3,607
2
14
25

only with the first pass works, 2 and 3 isn't necessary, this :) – Christopher Vivar Vivar Feb 12 '19 at 12:58
1

2 & 3 also needed because if you mentioned Context instead of Activity then your problem remain same! – Mayur Dabhi Feb 12 '19 at 13:51

score 0 · Answer 3 · edited Feb 12 '19 at 02:32

0

You can get the Context from your View like this:

@Override public void onClick(View v) { 
    int position = (Integer) v.getTag(); 
    final Object object = getItem(position); 

    switch (v.getId()) { 
        case R.id.list_delete_button: 
            AlertDialog.Builder builder = new AlertDialog.Builder(v.getContext()); 
            builder.show();
            break; 
    } 
}

edited Feb 12 '19 at 02:32

Christopher Vivar Vivar

210
2
12

answered Feb 11 '19 at 22:28

Jackey

3,184
1
11
12

the problem persist. I try, v.getContext(), MainActivity.getApplicationContext(), context, getContext() and all time is the same problem – Christopher Vivar Vivar Feb 11 '19 at 22:31
Sorry, didn't see that you already passed in a context through your constructor. It also looks like the crash you're getting isn't related to getting the context, but that the Activity that hosts the adapter doesn't exist anymore. Are you holding onto the adapter even after the activity has been destroyed, such as after a rotation change or etc? – Jackey Feb 11 '19 at 22:33
Now I added the MainActivity – Christopher Vivar Vivar Feb 12 '19 at 00:14
Why are you adding this into my answer instead of your question? – Jackey Feb 12 '19 at 00:31
my bad, now I fix it – Christopher Vivar Vivar Feb 12 '19 at 02:23

ॐ Rakesh Kumar · Answer 4 · 2019-02-13T03:45:34.967

0

You will have to use either Activity instance or can TypeCast Context to Activity like this following:

AlertDialog.Builder builder = new AlertDialog.Builder(YourActivity.this);

or

AlertDialog.Builder builder = new AlertDialog.Builder((Activity)context);

and Where you are showing AlertDialog then do something like this

if(!((Activity)context).isFinishing())
{
    builder.show(); 
}

You will not get that exception

edited Feb 13 '19 at 03:45

answered Feb 12 '19 at 05:36

ॐ Rakesh Kumar

1,318
1
14
24

I try this, but not work, I need give the context in the *MainActivity* to adapter with `this` – Christopher Vivar Vivar Feb 12 '19 at 12:56
@ChristopherVivarVivar, I have updated the answer, check If your issue not solved. – ॐ Rakesh Kumar Feb 13 '19 at 03:46

AlertDialog can't get context in custom adapter

4 Answers4