Question

片段：-

public class HomeProductFragment extends Fragment implements ActionBar.TabListener {

    private List<String> data = new ArrayList<>();

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        view = inflater.inflate(R.layout.fragment_home_product, container, false);


        userService = ApiUtils.getUserService();
        Call<ProductCategoryDetails> callCategory = userService.getProductCategoryJSON();
        callCategory.enqueue(new Callback<ProductCategoryDetails>() {
            @Override
            public void onResponse(Call<ProductCategoryDetails> call, Response<ProductCategoryDetails> response) {
                try {
                    if (response.body() != null && response.body().getData() != null) {
                        for(int j = 0;j<response.body().getData().getCategories().size();j++) {
                            productCategory = response.body().getData().getCategories().get(j).getMainCategory();
                            data.add(productCategory);
                        }
                        Log.d("SET321","==set=="+data);
                        viewPager = (ViewPager) view.findViewById(R.id.viewpager);
                        viewPagerAdapter = new ViewPagerAdapter(getFragmentManager());
                        viewPager.setAdapter(viewPagerAdapter);
                        viewPagerAdapter.setData(data); <-----------

                    } else
                        Toast.makeText(getContext(), "Error!======" + response.code(), Toast.LENGTH_SHORT).show();
                }catch (Exception e){
                    Log.d("TEST123","Exception");
                }
            }

            @Override
            public void onFailure(Call<ProductCategoryDetails> call, Throwable t) {
                Log.d("TAG","FailedCat");
            }
        });

ViewPagerAdapter：-

private List<String> data;

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    public void setData(List<String> data){
        this.data = data;
    }


    @Override
    public Fragment getItem(int position) {
        return TabFragment.getInstance(position);
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        String[] stockArr = new String[data.size()];
        return stockArr[position];
        //return data.get(position);

    }

    @Override
    public int getCount() {
        String[] stockArr = new String[data.size()];
        return stockArr.length;
        //return data.size();
    }

    public int getItemPosition(Object object) {
        String[] stockArr = new String[data.size()];
        return stockArr.length;
        //return data.size();
    }
}

错误：

java.lang.NullPointerException：尝试调用接口方法空对象引用上的'int java.util.List.size（）' 在com.custom_adapters.ViewPagerAdapter.getCount（ViewPagerAdapter.java:43）

Answer 1

您的数据列表可以作为构造函数的论点传递，即删除适配器中的setData方法并使构造函数为

Runas /user:domain\user "cmd /C echo Test > ""C:\Program Files\Install2AgentService\Install2AgentWinService.exe.config"""

Answer 2

要简单地修复它，请在{strong> 0 --> 0.0 1 --> 0.1 2 --> 0.2 3 --> 0.3 4 --> 0.4 5 --> 0.5 6 --> 0.6 7 --> 0.7 8 --> 0.8 9 --> 0.9 500 --> 50.0 501 --> 50.1 502 --> 50.2 503 --> 50.3 504 --> 50.4 505 --> 50.5 506 --> 50.6 507 --> 50.7 508 --> 50.8 509 --> 50.9 1000 --> 100.0 1001 --> 100.1 1002 --> 100.2 1003 --> 100.3 1004 --> 100.4 1005 --> 100.5 1006 --> 100.6 1007 --> 100.7 1008 --> 100.8 1009 --> 100.9之前执行viewPagerAdapter.setData(data);

Android将列表从片段传递到viewPagerAdapter

2 个答案: