Button (class) in Button cannot be applied to class

Question

I'm coding an Android app that uses an AsyncTask. I get the following error in the "onPostExecute" void :

Button (android.content.Context) in Button cannot be applied to >(com.****.OnlineProductList)

I already tried to change the "this" statement to "getContent()" and "MainAtivity.this". When I type in "get Content()" it says: cannot resolve When I type in "MainActivity.this" it says: MainActivity is not an enclosing class

    public class OnlineProductList extends AsyncTask<Void,Void,Void>{


        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);


            System.out.println("Program: " + productData.length / 3 + " Products found");

//create product objects



            Product[] product = new Product[productData.length / 3];
            for (int i = 0; i < product.length; i++) {

                product[i] = new Product(productData[3 * i], productData[1 + 3 * i], Boolean.parseBoolean(productData[2 + 3 * i]));

            }

            //create buttons for available products

            MainActivity.productButton = new Button[product.length];

            for (int i = 0; i < productData.length; i++) {

                MainActivity.productButton[i] = new Button(this);
                MainActivity.productButton[i].setWidth(MainActivity.orderHorizontalLayout.getWidth());
                MainActivity.productButton[i].setHeight(MainActivity.orderHorizontalLayout.getHeight() / 10);
                MainActivity.productButton[i].setText(product[i].name);

                MainActivity.orderHorizontalLayout.addView(MainActivity.productButton[i]);

            }
        }
    }

The error occurs in this line:

MainActivity.productButton[i] = new Button(this);

Answer 1

You need to pass a Context for the creation of Button, currently you're passing the OnlineProductList(AsyncTask) object.

You could just pass a Context instance as a constructor parameter (and keep a WeakReference to it to avoid memory leaks) to the OnlineProductList and use that Context to create your Button.

Something along the following lines should work,

    public class OnlineProductList extends AsyncTask<Void,Void,Void>{
        private WeakReference<Context> contextRef;

        public OnlineProductList(Context context) {
            contextRef = new WeakReference<>(context);
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);


            System.out.println("Program: " + productData.length / 3 + " Products found");

//create product objects



            Product[] product = new Product[productData.length / 3];
            for (int i = 0; i < product.length; i++) {

                product[i] = new Product(productData[3 * i], productData[1 + 3 * i], Boolean.parseBoolean(productData[2 + 3 * i]));

            }

            //create buttons for available products

            Context context = contextRef.get();
            if (context != null) {
                MainActivity.productButton = new Button[product.length];

                for (int i = 0; i < productData.length; i++) {

                    MainActivity.productButton[i] = new Button(this);
                    MainActivity.productButton[i].setWidth(MainActivity.orderHorizontalLayout.getWidth());
                    MainActivity.productButton[i].setHeight(MainActivity.orderHorizontalLayout.getHeight() / 10);
                    MainActivity.productButton[i].setText(product[i].name);

                    MainActivity.orderHorizontalLayout.addView(MainActivity.productButton[i]);
                }
            }
        }
    }