Alert Dialog Exception “Unable to add windows — token null is not for an application”, what context should I give?

Question

I know that some people asked the same question before, I checked them and it didn't help, so I'm building an Android application, and I'm using the list view, I added a button in the items, to delete the entry and I want to show a confirmation dialog.

When I press that button the application crashes, when I searched for the problem I found that there is a problem in the context I'm passing, I tried so many things but I couldn't find the solution, here is the code. This is the item Adaptor code:

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    final View v;

    LayoutInflater layoutInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    v = layoutInflater.inflate(R.layout.product_cell, null);

    final Produit currentProduit = getItem(position);
    getviews(v);
    fillViews(currentProduit);

    supprimer.setOnClickListener(new Button.OnClickListener() {
        @Override
        public void onClick(View view) {
            MyMethodsClass.displayToast("i'm working dude", view.getContext());
            AlertDialog.Builder confirmDialog;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
                confirmDialog = new AlertDialog.Builder(v.getContext(), android.R.style.Theme_Material_Dialog_Alert);
            else
                confirmDialog = new AlertDialog.Builder(v.getContext());

            confirmDialog.setTitle("Supprimer?");
            confirmDialog.setMessage("Etes vous sur de vouloir supprimer le produit" + currentProduit.getNomP());
            confirmDialog.setNegativeButton("Annuler", new AlertDialog.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            });
            confirmDialog.setPositiveButton("Confirmer", new AlertDialog.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    deleteProduct(currentProduit);
                    productsAdapter.remove(currentProduit);
                    productsAdapter.notifyDataSetChanged();
                }
            }).show();
        }
    });

    return v;
}

and this is the code of the activity using it:

public class Stock extends AppCompatActivity implements View.OnClickListener {

String barcode;
EditText codebare, nomproduit;
Button scanbut, rechbut;
ListView stockProdList;
ArrayList<Produit> productsArray;
public static ProductsAdapter productsAdapter;
public Context context = this;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_supprimer_produit);

    barcode = getIntent().getStringExtra("code");
    codebare = (EditText) findViewById(R.id.rechStockEditScan);
    nomproduit = (EditText) findViewById(R.id.rechStockNomP);
    scanbut = (Button) findViewById(R.id.scannStock);
    rechbut = (Button) findViewById(R.id.rechercheStock);
    stockProdList = (ListView) findViewById(R.id.listStockSup);

    productsAdapter = new ProductsAdapter(getApplicationContext(), 0);
    productsArray = new ArrayList<>();

    if (!TextUtils.isEmpty(barcode))
        codebare.setText(barcode);

    stockProdList.setAdapter(productsAdapter);
    fillListView();
}

void searchProduct() {
    productsArray.clear();
    String query = "SELECT * FROM produit WHERE ";
    if (!nomproduit.getText().toString().isEmpty() && !codebare.getText().toString().isEmpty()) {
        query += "NOMP='" + nomproduit.getText().toString() + "' AND BAREC='" + codebare.getText().toString() + "';";
    } else if (!nomproduit.getText().toString().isEmpty()) {
        query += "NOMP='" + nomproduit.getText().toString() + "';";
    } else if (!codebare.getText().toString().isEmpty()) {
        query += "BAREC='" + codebare.getText().toString() + "';";
    } else {
        MyMethodsClass.displayToast("FAUT REMPLIRE AU MOIN UN CHAMP POUR RECHERCHER", this);
    }
    try {
        Connection connection = DataBaseConnection.CONNECT();
        Statement st = connection.createStatement();
        ResultSet rs = st.executeQuery(query);

        while (rs.next()) {
            productsArray.add(new Produit(rs.getString("NOMP"), rs.getString("BAREC"), rs.getString("PHOTOP"), rs.getFloat("PRIXA"), rs.getFloat("PRIXG"),
                    rs.getFloat("PRIXD"), rs.getInt("QUANTITEP"), rs.getInt("NBREMBA"), rs.getInt("IDP")));
        }
    } catch (Exception e) {
        Log.e("ERROR WHILE SEARCHING FOR DATA LINE 70", e.getMessage());
    }
    Log.e("what the hell?", "it's running");
    productsAdapter.clear();
    productsAdapter.addAll(productsArray);
    stockProdList.setAdapter(null);
    stockProdList.setAdapter(productsAdapter);
}

and here is the log:

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.simapps.mobilestock, PID: 9260
              android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
                  at android.view.ViewRootImpl.setView(ViewRootImpl.java:684)
                  at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:289)
                  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85)
                  at android.app.Dialog.show(Dialog.java:311)
                  at android.app.AlertDialog$Builder.show(AlertDialog.java:993)
                  at Adapters.ProductsAdapter$1.onClick(ProductsAdapter.java:87)
                  at android.view.View.performClick(View.java:4855)
                  at android.view.View$PerformClick.run(View.java:20287)
                  at android.os.Handler.handleCallback(Handler.java:815)
                  at android.os.Handler.dispatchMessage(Handler.java:104)
                  at android.os.Looper.loop(Looper.java:194)
                  at android.app.ActivityThread.main(ActivityThread.java:5637)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at java.lang.reflect.Method.invoke(Method.java:372)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)

Answer 1

To show a Dialog you need to use the Activity context. Here you're using the Application context which is incorrect.

productsAdapter = new ProductsAdapter(getApplicationContext(), 0);

To make it work change the above line to use the Activity context. Since this call is made inside an Activity you can use:

productsAdapter = new ProductsAdapter(this, 0);

But this is not the best way to do so because your parameter type is Context and not Acticity and as it's happening to you, the context may be incorrect.

A better idea is to provide a click listener callback to your Activity and manage the Dialog inside the Activity instead of the Adapter .