我正在开发一个在ViewPager中有3个页面的应用程序。但我在刷页面时无法更改片段。请任何人帮助我理解如何做到这一点....
public class HomePage extends FragmentActivity {
ViewPager viewPager;
PagerTabStrip pagerTabStrip;
PagerAdapter adapter;
TextView pageTag;
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
/*
* ActionBar Fragment Class
*/
ActionBar actionBar;
Fragment fragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.homepage);
/*
* Setting adapter for viewPager
*/
viewPager = (ViewPager) findViewById(R.id.pager);
adapter = new TabView(getSupportFragmentManager());
viewPager.setAdapter(adapter);
/*
* Setting coustom Animation for ViewPager
*/
viewPager.setPageTransformer(true, new CoustomPageTransform());
/*
* All properties for pagerTabStrip //
*/
pagerTabStrip = (PagerTabStrip) findViewById(R.id.tabstrip);
pagerTabStrip.setDrawFullUnderline(true);
pagerTabStrip.setTabIndicatorColor(Color.parseColor("#33B5E5"));
pagerTabStrip.setTextSpacing(80);
pagerTabStrip.setTextColor(Color.parseColor("#666666"));
/*
* Setting Up ActionBar Fragment
*/
if (savedInstanceState != null) {
actionBar = new ActionBar();
fragmentManager = getSupportFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_container, actionBar)
.commit();
}
}
public class TabView extends FragmentStatePagerAdapter {
public TabView(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
@Override
public Fragment getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "TASKS";
case 1:
return "WORKBOOK";
case 2:
return "ITINERARY";
default:
break;
}
return null;
}
}
public class CoustomPageTransform implements ViewPager.PageTransformer {
float MIN_SCALE = 0.85f;
float MIN_ALPHA = 0.5f;
@Override
public void transformPage(View view, float position) {
int pageHeight = view.getHeight();
int pageWidth = view.getWidth();
if (position < -1) {
view.setAlpha(0);
} else if (position <= 1) {
float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
float vertMargin = pageHeight * (1 - scaleFactor) / 2;
float horMargin = pageWidth * (1 - scaleFactor) / 2;
if (position < 0) {
view.setTranslationX(horMargin - vertMargin / 2);
} else {
view.setTranslationX(-horMargin + vertMargin / 2);
}
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
view.setAlpha(MIN_ALPHA + scaleFactor - MIN_SCALE
/ (1 - MIN_SCALE) * (1 - MIN_ALPHA));
} else {
view.setAlpha(0);
}
}
}
}
答案 0 :(得分：1)
您没有返回任何片段......您正在适配器中返回null，所以当然您不会看到/做任何事情......
在您的适配器中，您应该保留所需片段的列表/集合，并根据该位置返回它们。
答案 1 :(得分：0)
尝试这种方式！我不太确定你想做什么，但是使用这段代码你可以更改并滑动＆＃34;页面＆＃34;
public class MainActivityEPG extends FragmentActivity {
SectionsPagerAdapter mSectionsPagerAdapter;
static Context c;
PagerTitleStrip pagerTabStrip;
static ViewPager mViewPager;
@Override
public void onBackPressed() {
MainActivity2.deleteBackground(false);
finish();
super.onBackPressed();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.epg_ui);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
pagerTabStrip = (PagerTitleStrip) findViewById(R.id.pager_title_strip);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
@Override
public int getCount() {
return 6;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
pagerTabStrip.setAlpha(150f);
pagerTabStrip.setBackgroundColor(Color.parseColor("#80000000"));
switch (position) {
case 0:
return getString(R.string.title_section1);
case 1:
return getString(R.string.title_section2);
case 2:
return getString(R.string.title_section3);
case 3:
return getString(R.string.title_section4);
case 4:
return getString(R.string.title_section5);
case 5:
return getString(R.string.title_section6);
}
return null;
}
}
public static class DummySectionFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
return rootView;
}
}
}