我使用Eclipse模板生成滑动布局。 我用开关/盒子将页面从3扩展到5。 我还将一个imageview放入虚拟片段。 现在我有5个具有相同图像的片段。如何管理单个实例，以便我可以将不同的内容放入其中？
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the five
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
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() {
// Show 3 total pages.
return 5;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
case 3:
return getString(R.string.title_section4).toUpperCase(l);
case 4:
return getString(R.string.title_section5).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* 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);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
return rootView;
}
}
}
答案 0 :(得分：1)
这取决于数据的不同程度。如果每个片段只有一个ImageView，你可以像你正在做的那样重复使用相同的片段。您只需要检查getItem方法中的位置，并通过bundle将不同的数据发送到该片段的实例。然后在DummySectionFragment中，您可以检查传递的数据，即使它只是位置，也可以根据数据/位置添加不同的图像。
如果每个片段上的内容不同，那么您应该为每个片段创建一个不同的片段。因此，不是只有DummySectionFragment，而是每个部分都有一个不同的片段，并根据您的需要为每个片段分配一个新的布局。
除非您只使用该位置修改每个片段中的数据，否则您的getItem应如下所示：
@Override
public Fragment getItem(int position) {
Fragment fragment = null;
Bundle args = new Bundle();
switch(position){
case 0:
fragment = new DummySectionFragment();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
break;
case 1:
fragment = new DummySectionFragment();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
break;
case 2:
fragment = new DummySectionFragment();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
break;
}
return fragment;
}
唯一的区别是，如果你采用第二种方法，每种情况下你将实例化一个不同的片段而不是同一个片段。
如果您只想根据片段的位置更改图像，可以保持代码相同，只需检查DummySectionFragment中的位置，如下所示：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
int position = Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER))
if(position == 1){
//Your on the first tab..
}
return rootView;
}
祝你好运！