android - Problem displaying DialogFragment from button in Adapter Android

Question

I want to display a DialogFragment from my adapter button. I have created a DialogFragment class inside the adapter itself and I want it to show me the dialog when I press the button, but I get this error:

java.lang.ClassCastException: android.app.Application cannot be cast to androidx.appcompat.app.AppCompatActivity
        at com.example.karate_manager.Adapters.AdapterMarket$1.onClick(AdapterMarket.java:106)

This is my adapter:

public class AdapterMarket extends ArrayAdapter{
private FragmentManager fm;
    Context context;
    int item_Layaut;
    ArrayList<Karateka> data;
    ApiUtils apiUtils;

  public AdapterMarket(@NonNull Context context, int resource, @NonNull ArrayList objects, FragmentManager fm) {
        super(context, resource, objects);
        this.context = context;
        this.item_Layaut = resource;
        this.data = objects;
        this.fm = fm;
    }

    public void setData(MarketResponse data) {
        if(data!=null){
            this.data = data.getKaratekas();
            this.notifyDataSetChanged();
        }
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        if (convertView == null) {
            LayoutInflater layoutInflater = LayoutInflater.from(context);
            convertView = layoutInflater.inflate(item_Layaut, parent, false);
        }

        String value = String.valueOf(data.get(position).getValue());
        Button buttonValue = convertView.findViewById(R.id.item_button_value_karateka);
        buttonValue.setText(value);

        popupBidKarateka(buttonValue);

        return convertView;
    }

    public void popupBidKarateka(Button buttonValue){
        buttonValue.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                FragmentActivity activity = (FragmentActivity)(context);
                fm = activity.getSupportFragmentManager();
                DialogFragment newFragment = new BidKaratekaDialogFragment();
                newFragment.show(fm, "bid" );
            }
        });
    }
}

And this is the reference in the Fragment:

     FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
        adapterMarket = new AdapterMarket(getActivity().getApplicationContext(), R.layout.item_market_layout, marketResponse.getKaratekas(), fragmentManager);

标签： androidlistviewandroid-fragmentsandroid-arrayadapter

Answer 1

               public void onClick(View view) {
                Application activity1 = (Application) view.getContext(); // bad

                FragmentActivity activity = (FragmentActivity)(context); // context must come from FragmentActivity

// 我假设 FragmentActivity 是您调用适配器的类。

                FragmentManager fm = activity.getSupportFragmentManager();
                DialogFragment newFragment = new BidKaratekaDialogFragment();
                newFragment.show(fm, "bid" );
            }
        });

智者说。。

一个上下文并不总是一个活动，即使你在一个活动中。它可以是一个应用程序，也可以是另一个上下文的包装器。将 Context 强制转换为 Activity 几乎总是错误的。如果你绝对需要，你应该传入一个 Activity 作为参数，而不是一个 Context。或者更好的是，直接传递支持片段管理器而不是活动，因为这就是你所需要的。

public AdapterMarket(@NonNull Context context, FragmentManager fm, int resource, @NonNull ArrayList objects) {
        super(context, resource, objects);
        this.context = context;
        this.fm = fm;
        this.item_Layaut = resource;
        this.data = objects;
    }

// 比如说，Afragment 正在调用适配器。

AFragment.class
FM fm = getActivity.getSupportFM/getFM();
AdapterMarket market = new AdapterMarket(someContext, fm, ....)