浮动按钮在OnClick函数上显示NullPointer异常

Question

public class MaterialUpConceptFakePage extends Fragment {

    private RecyclerView mRootView;
    private ViewPager vpCustomerTestimonials;
    private CirclePageIndicator cpiBanner;
    private CustomerTestimonialsPagerAdapter customerTestimonialsPagerAdapter;
    FloatingActionButton FAB;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_page, container, false);

        mRootView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
        vpCustomerTestimonials = (ViewPager) rootView.findViewById(R.id.vpCustomerTestimonials);
        cpiBanner = (CirclePageIndicator) rootView.findViewById(R.id.cpiBanner);

        FAB = (FloatingActionButton) rootView.findViewById(R.id.fab);
        initRecyclerView();
        initslideViewpager();
        FAB.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(getActivity(), FAQAndTermsOfUse.class);
                startActivity(i);
            }
        });

        return rootView;
    }
}

这是我的代码，当我应用On Click函数然后它抛出空指针异常浮动按钮单击当应用程序启动时，我删除onClick功能然后它的工作正常请告诉我我做错了为什么它显示异常

Answer 1

检查您的FAQAndTermsOfUse.class

注意：它应该扩展AppCompatActivity

例如：

public class FAQAndTermsOfUse extends AppCompatActivity
{

{

并检查您的清单，您是否已在清单中声明此活动。

<activity
            android:name=".FAQAndTermsOfUse "
            android:label="@string/app_name">
</activity>

Answer 2

Fragment允许添加FloatingActionButton。我认为您的问题可能在FAQAndTermsOfUse.class中，请验证在清单文件中添加FAQAndTermsOfUse？

Answer 3

检查您的xml文件并确保它包含ID为'R.id.fab'的FAB。