Android Fragment实现对话片段监听器“空指针异常”

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    try {
        mListener = (MyListener) context;
    } catch (ClassCastException e) {
        throw new ClassCastException(context.toString() + " must implement MyListener");
    }
}

if (mListener != null) {
    mListener.onFragmentInteraction(data);
}

public class MainActivity extends AppCompatActivity implements MyListener {
    // ...

    @Override
    public void onFragmentInteraction(String data) {
        // 处理Fragment的交互逻辑
    }
}