java.lang.NullPointerException：尝试调用虚拟方法'void com.example.fyp.MainActivity2.getTotalPrice1android.content.Context'

如何解决java.lang.NullPointerException：尝试调用虚拟方法'void com.example.fyp.MainActivity2.getTotalPrice1android.content.Context'

从适配器调用活动函数时获取空指针异常

功能

        for (int i = 0; i < cartArrayList.size(); i++) {
            cartModel = cartArrayList.get(i);
            if (cartModel.getProductInfoModel() != null) {
                total += Double.parseDouble(cartArrayList.get(i).getProductInfoModel().getPRICE()) * (cartArrayList.get(i).getQuantity());
            } else if (cartModel.getDealinfomodel() != null) {
                total1 += Double.parseDouble(cartArrayList.get(i).getDealinfomodel().getTOT_SALE()) * (cartArrayList.get(i).getQuantity());
            }
        }
        int IntValue = (int) (total+total1);
        carttotalprice.setText("" + IntValue);
    }```


**adapter where i call my function**
``` ((MainActivity2)activity).getTotalPrice1(context);```

``` ```