添加子片段父片段withing在Android上ViewPager [英] Adding child Fragment to Parent Fragment withing a ViewPager in Android
问题描述
我正在开发，有一些标签的应用程序，像这样
I'm developing an app that has some tabs,something like this
每个标签是一个片段，每个片段显示的文章，类别和其他的一些信息列表视图。 我试图做的是，当我在一个项目挖掘从列表视图中的片段，打开一个新的片段与完整的文章或更多信息即可。我读过，这与嵌套的片段做的，我必须使用的方法 getChildFragmentManager（）。我使用的是ViewPager，以显示我的标签片段，这是我的主要活动：
Each tab is a Fragment, and each fragment displays a listview of articles, categories and some other information. What I'm trying to do is to when I tap in an item from the listview in a fragment, open a new Fragment with the full article or more info. I've read that this has to do with nested Fragments, and that I have to use the method getChildFragmentManager(). I am using a ViewPager to display my fragments in the tabs, this is my main Activity:
public class MainActivity extends FragmentActivity{
private String tabs[]={"Tab1, Tab2,.<other Fragments>..,VideosFragment"};
ViewPager viewPager=null;
FragmentManager fragmentManager=getSupportFragmentManager();
android.support.v4.app.FragmentTransaction ft=fragmentManager.beginTransaction();
AdapterView adapterView;
public static final int TIME_ENTRY_REQUEST_CODE=1;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager=(ViewPager)findViewById(R.id.pager);
viewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener(){
public void onPageSelected(int position){
getActionBar().setSelectedNavigationItem(position);
}
});
viewPager.setAdapter(new AdapterView(fragmentManager));
viewPager.setOffscreenPageLimit(tabs.length);
adapterView=new AdapterView(getSupportFragmentManager());
/*initialization of the action bar: color, icon & title.*/
final android.app.ActionBar actionbar=getActionBar();
ColorDrawable color=new ColorDrawable(Color.parseColor("#cd853f"));
actionbar.setBackgroundDrawable(color);
actionbar.setTitle("Title");
ActionBar.TabListener tabListener=new ActionBar.TabListener() {
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
viewPager.setCurrentItem(tab.getPosition());
ft=getFragmentManager().beginTransaction();
//ft.replace(layouts[tab.getPosition()], (adapterView.getItem(tab.getPosition()));
ft.commit();
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
};
/*Displaying Tabs for the app */
for(int i=0;i<tabs.length;i++)
actionbar.addTab(actionbar.newTab().setText(tabs[i]).setTabListener(tabListener));
actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionbar.setSelectedNavigationItem(position);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
}
修改，当我在ListView的项目挖掘，我想开一个新的片段，这是我的适配器为ListView：
} and when I tap in an item of a listview, I want to open a new Fragment, this is my adapter for the listView:
public class ItemAdapter extends BaseAdapter implements OnItemClickListener{
Item item=new Item();
private ArrayList<Item> news=new ArrayList<Item>();
private static final int NO_PICTURE_VIEW=0;
private static final int PICTURE_VIEW=1;
public ItemAdapter(Context context,ArrayList<Item> items) {
super();
news.addAll(items);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return news.size();
}
@Override
public Item getItem(int index) {
// TODO Auto-generated method stub
return getItem(index);
}
@Override
public long getItemId(int index) {
// TODO Auto-generated method stub
return index;
}
public int getViewTypeCount() {
return 2;
}
public int getItemViewType(int position) {
Item article=news.get(position);
// if(article.getImageUrl()!=null&&!article.getImageUrl().equals("")&&article.getImageUrl().indexOf("no_pic.png")==-1)//if there's no pic
if(article.getImage()!=null)
return PICTURE_VIEW;
else
return NO_PICTURE_VIEW;
}
@Override
public View getView(int index, View view, ViewGroup parent) {
item=news.get(index);
int type=getItemViewType(index);
if(view==null){
LayoutInflater inflater=LayoutInflater.from(parent.getContext());
if(type==NO_PICTURE_VIEW){
view=inflater.inflate(R.layout.item_no_picture_list,parent,false);
TextView titleView=(TextView)view.findViewById(R.id.titleNoPicture);
titleView.setText(item.getTitle());
}
else{
view=inflater.inflate(R.layout.item_picture_list,parent,false);
TextView titleView=(TextView)view.findViewById(R.id.titleArticle);
ImageView image=(ImageView)view.findViewById(R.id.imageItem);
titleView.setText(item.getTitle());
image.setImageBitmap(item.getImage());
}
}
return view;
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Log.d("ItemAdapter","clicked on "+position);
}
}
这是在ViewPager的片段之一：
This is one of the fragments in the ViewPager:
public class VideosFragment extends Fragment{
static ListView listvideo;
ItemAdapter itemAdapter;
Context context;
Activity activity;
FragmentManager fm=getChildFragmentManager();
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState){
super.onCreateView(inflater, container, savedInstanceState);
View view=inflater.inflate(R.layout.videos_activity, container,false);
listvideo=(ListView)view.findViewById(R.id.videoslist);
context=getActivity();
setRetainInstance(true);
return view;
}
public void onViewCreated(View view, Bundle savedInstanceState){
super.onViewCreated(view, savedInstanceState);
ViewPager vp=(ViewPager)view.findViewById(R.id.pager);
vp.setAdapter(new AdapterView(fm));
}
public void displayVideos(final List<Item> videos){
try {
if(videos==null || videos.size()==0){
Log.d("videos activity","the list is null!!");
}
} catch (Exception e) {
e.printStackTrace();
}
for(int i=0;i<videos.size();i++){
}
itemAdapter=new ItemAdapter(context,(ArrayList<Item>) videos);
listvideo.setAdapter(itemAdapter);
listvideo.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(android.widget.AdapterView<?> parent,
View view, int position, long id) {
Log.d("HomeActivity","Tapped on "+position);
//FragmentTransaction ft=fm.beginTransaction();
//Fragment vp=new VideoPlayer();
//ft.add(R.id.videoview, vp);
///ft.addToBackStack("VideosActivity");
//ft.commit();
}
});
}
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return 4;
}
@Override
public Fragment getItem(int position) {
return new VideoPlayer();//ChildFragment
}
}
}
注释行的fragmenttransaction，之后给了我一个NPE的线条，所以我想我失去了一些东西。的VideoPlayer是ChildFragment，在那一刻我只希望能够显示片段没有的信息，只知道它是如何工作。这是我的适配器的片段：
The commented lines for fragmenttransaction and the lines after that gave me a NPE, so I guess I'm missing something. VideoPlayer is the ChildFragment, and at the moment I only want to be able to display the fragment without info, just to know how it works. This is my adapter for the fragments:
class AdapterView extends FragmentPagerAdapter{
public static int NUM_ITEMS=3;
Tab1 tab1=new Tab1();
Tab2 tab2=new Tab2();
VideoFragment va=new VideoFragment();
public AdapterView(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int i) {
Log.d("FRAGMENT","EN: "+i);
switch(i){
case 0:
return tab1;
case 1:
return tab2;
case 2:
return va;
default:
return null;
}
}
@Override
public int getCount() {
return NUM_ITEMS;
}
}
我还没有发现什么，我正在寻找一个教程，所以我希望你们中的一些可以帮助我理解它是如何工作的。我知道这是可能的，因为在Android 4.2 API允许它。我只是想知道嵌套的片段是如何工作的，以及如何使用它们我的应用程序需要它的方式。任何信息都是AP preciated，谢谢。
I haven't found a tutorial for what I'm looking for, so I hope some of you can help me understand how it works. I know it's possible, since the Android API 4.2 allows it. I just want to know how the nested fragments work, and how to use them the way my apps needs it. Any information is appreciated, thanks.
推荐答案
如果你想要的是更换一个片段与另一片段viewpager里面，看一看的这个。不过我建议你创建另一个片段（容器），并移动viewpager和片段这个新的片段里面：
If what you want is replace a fragment inside the viewpager with another fragment, take a look at this. However I would suggest you to create another Fragment (a container), and move your viewpager and fragments inside of this new fragment:
当用户点击列表中的项目通过这种方式，可以取代 MainFragment 与详细信息片段
This way when the user clicks an item of a list, you can replace the MainFragment with a Details Fragment.
关于 ChildFragmentManager（），当你嵌套片段使用它。如果你改变你的执行情况我建议，你需要一个ChildFragmentManager传递到您的PagerAdapter：
About the ChildFragmentManager(), it is used when you have nested fragments. If you change your implementation as I suggested, you would need to pass a ChildFragmentManager to your PagerAdapter:
viewPager.setAdapter(new AdapterView(getChildFragmentManager()));
在 VideosFragment 约code你的注释行另一件事。让你的活动提交的，而不是做它里面的片段片段交易。为了更好的说明，请参阅这个。
Another thing about your commented lines of code inside VideosFragment. Make your activity commit the fragment transaction instead of doing it inside the Fragment. For a better explanation, read this.
这篇关于添加子片段父片段withing在Android上ViewPager的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
