我有以下问题。我有一个带有 viewpager 和两个标签的应用程序。这两个选项卡是两个列表片段。现在我希望如果用户在第一个选项卡中选择一个项目，则在第二个选项卡中选择第 5 个项目。（第二个选项卡是第一项文本的翻译）。我的问题是，当我在第一个选项卡中选择一个项目，现在切换到第二个选项卡时，没有任何选择。当我单击第一个选项卡中的某些内容时，我调用了 Parent 活动中的一个函数，该函数调用了第二个片段中的一个函数，该函数应该选择第 5 个项目。这是片段活动的代码：
public class Dailyquran extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
public ArrayList<Tweet> tweets = new ArrayList<Tweet>();
public ArrayList<Tweet> tweets2 = new ArrayList<Tweet>();
//private static ArrayList<String> roomList;
public String a;
public static int laenge_inhalt;
public static int selected;
public static String sure_media;
public static String vers_media;
String koran_filename;
//int tabwahl=0;
int playstatus=0;
MediaPlayer mp = new MediaPlayer();
MenuItem playMenu;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.activity_dailyquran, menu);
playMenu = menu.findItem(R.id.menu_play);
return true;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("Daily Quran");
setContentView(R.layout.activity_dailyquran);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the action bar.
final ActionBar actionBar = getActionBar();
// set the app icon as an action to go home
actionBar.setDisplayHomeAsUpEnabled(true);
//enable tabs in actionbar
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// 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 (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
// listener for when this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
main();
}
/* WEITER UNTEN SIND DIE TABSELECTED FUNKTIONEN !!!!
//@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
// @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 onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private FragmentTransaction mCurTransaction = null;
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE; //To make notifyDataSetChanged() do something
}
@Override
public Fragment getItem(int i) {
// Fragment building_fragment = new BuildingFragment();
Fragment room_fragment = new RoomFragment();
Fragment transl_fragment = new TransliterationFragment();
// Fragment device_fragment = new DeviceFragment();
Bundle args = new Bundle();
switch(i){
case 0:
room_fragment.setArguments(args);
return room_fragment;
case 1:
return transl_fragment;
case 2:
// args.putInt(RoomFragment.ARG_SECTION_NUMBER, i);
// room_fragment.setArguments(args);
return room_fragment;
default: return null;
}
}
@Override
public int getCount() {
return 2;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0: return "a";
case 1: return "b";
case 2: return "c";
}
return null;
}
@Override
public Object instantiateItem(View container, int position) {
if (mCurTransaction == null) {
mCurTransaction = getSupportFragmentManager().beginTransaction();
}
// TODO Auto-generated method stub
Fragment fragment = getItem(position);
if (fragment!=null){
System.out.println("Fragment Found!");
mCurTransaction.attach(fragment);
}
return fragment;//super.instantiateItem(container, position);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.menu_play:
play();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem switchButton = menu.findItem(R.id.menu_play);
}
public class Tweet {
String content;
String sure;
String vers;
}
public class Tweet2 {
String content;
String sure;
String vers;
}
public void onTabReselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
mViewPager.setCurrentItem(tab.getPosition());
}
public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {
// TODO Auto-generated method stub
}
//HERE IS THE CODE FOR SELECTING THE SECOND ITEM
public void one_changed()
{
TransliterationFragment fragment_meaning = (TransliterationFragment) getSupportFragmentManager().findFragmentById(R.id.myfragment2);
Toast.makeText(getApplicationContext(),"Change Selection", Toast.LENGTH_SHORT).show();
fragment_meaning.change_selected(); // do what updates are required
}
这是第二个片段的相关代码，我可以在控制台中看到字符串“Hallo”，因此确实调用了该函数，但未选择该项目。
public void change_selected()
{
System.out.println("Hallo");
ListView list=getListView();
list.setSelection(4);
}