我有一个承载多个片段的 viewpager。其中之一,Frag1,应该接收一个带有数据的对象并用该数据填充一些 EditText。
问题是,当我尝试从 Activity 访问片段时,getView() 总是返回 null,从而无法调用 Frag1 类的方法。我正在使用 LogCat 检查其他变量是否为空,但问题似乎来自 getView() 检查。
知道为什么它为空吗?
活动代码
(...)
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_form1);
mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
final ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAppSectionsPagerAdapter);
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
// When swiping between different app sections, select the corresponding tab.
// We can also use ActionBar.Tab#select() to do this if we have a reference to the
// Tab.
actionBar.setSelectedNavigationItem(position);
}
});
public static class AppSectionsPagerAdapter extends FragmentPagerAdapter {
public AppSectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new Frag1();
case 1:
return new Frag2();
case 2:
return new Frag1();
case 3:
return new Frag1();
default:
return new Frag1();
}
}
@Override
public int getCount() {
return 4;
}
@Override
public CharSequence getPageTitle(int position) {
return "Section " + (position + 1);
}
}
public void Populate(Patient patient) {
Frag1 fragment =
(Frag1) mAppSectionsPagerAdapter.getItem(0);
Log.d(patient.getName(), "data check");
Log.d(fragment.hello(), "fragment check");
if (fragment.getView() == null) {
Log.d("*** DEBUG ***", "found the problem champ");
}
if(fragment != null) // could be null if not instantiated yet
{
if(fragment.getView() != null)
{
// no need to call if fragment's onDestroyView()
//has since been called.
fragment.setName(patient.getName());
Log.d(patient.getName(), "supbrah");// do what updates are required
}
}
}
片段代码
public class Frag1 extends Fragment {
EditText name;
Spinner spinner;
AutoCompleteTextView textView;
AutoCompleteTextView textView1;
Spinner spinner1;
AutoCompleteTextView textView2;
View v;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v = inflater.inflate(R.layout.activity_form, container, false);
name = (EditText) v.findViewById(R.id.name_edit);
return v;
}
public String hello() {
return "sup brah";
}
public String getName() {
String patient = name.getText().toString();
return patient;
}
public void setName(String text) {
name.setText(text, TextView.BufferType.EDITABLE);
}
}