我已经看到了我的问题的相对帖子,但它不能解决我的问题。 我试图用3片段获得滑动视图。 在主片段,我有这样的:FragmentStatePagerAdapter没有调用getItem()
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View vue = inflater.inflate(R.layout.fragment_conversions, container, false);
ConversionsPagerAdapter cPageAdapter = new ConversionsPagerAdapter(getActivity().getSupportFragmentManager());
ViewPager vp = vue.findViewById(R.id.conversionsPager);
cPageAdapter.getItem(0);
vp.setAdapter(cPageAdapter);
Button convKmhKts = (Button) vue.findViewById(R.id.convKmhKts);
convKmhKts.setText("...");
...
这里是类我FragmentStatePagerAdapter的:
public class ConversionsPagerAdapter extends FragmentStatePagerAdapter{
public ConversionsPagerAdapter(FragmentManager fm) {
super(fm);
Log.i("ARKA", "FragmentStatePagerAdapter CONSTRUCTOR");
}
@Override
public Fragment getItem(int i) {
return ConversionFragment.newInstance(i);
}
@Override
public int getCount() {
return 1;
}
}
而且finnaly其显示的标签中的片段:
public class ConversionFragment extends Fragment {
public static final String ID_CONVERSION = "id_conversion";
public static ConversionFragment newInstance(int pos) {
ConversionFragment stf = new ConversionFragment();
Bundle args = new Bundle();
args.putInt("pos", pos);
stf.setArguments(args);
return stf;
}
public ConversionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
// The last two arguments ensure LayoutParams are inflated
// properly.
Bundle args = getArguments();
int idConversion = args.getInt(ID_CONVERSION);
Log.i("idConversion", String.valueOf(idConversion));
int idVue;
switch (idConversion){
case 0: idVue = R.layout.fragment_conversions_vitesse;
break;
case 1: idVue = R.layout.fragment_conversions_vitesse;
default: idVue = R.layout.fragment_conversions_vitesse;
break;
}
View rootView = inflater.inflate(idVue, null);
return rootView;
}
}
事实是,getItem()永远不会被调用。 我尝试getChildFragmentManager()来改变getActivity()getSupportFragmentManager(),但似乎这不是好办法... 当我试图进入电影我的按钮,我得到这个:
的java.lang。的NullPointerException:尝试上的空对象引用
在行调用虚拟方法“无效android.widget.Button.setOnClickListener(android.view.View $ OnClickListener)”,其中我使用的按钮。
嗨,谢谢你的回答,它只是为了一个测试,我忘了重新这一行,但我会尝试你的idera。 –
我尝试过,但我仍然是nullpointerexception ... –