我在一个活动中有两个片段，main_activity.xml中有一个ViewPager元素。我创建了两个不同的类，它们为每个片段释放Fragment类并覆盖onCreateView方法。第一个片段是频道列表。所以这是一个列表视图，它的每一行都包含一个textview和一个按钮。我想当用户单击按钮时，将行传递给第二个片段中的listView。我在ChannelsFragment中创建了一个名为 FavButtonClickedListener 的接口，并在 MainActivity.java 中覆盖了此接口。然后我将 onAttach（）方法添加到ChannelsFragment中以引用MainActivity。在ChannelsFragment类的Adapter的getView方法中，我已经将clicklistener设置为每行中的imageButtons，并且我调用了 whenFavButtonClicked.onFavButtonClicked（）; 我的代码适用于SharedPreferences hovewer我需要重启应用程序以查看更改在收藏夹列表中。我想动态添加行。我不知道我错在哪里请帮助我
ChannelsFragment：
public class ChannelsFragment extends Fragment {
ViewGroup rootVg;
Context context;
FavButtonClickedListener whenFavButtonClicked;
private final List<String> favValues = new ArrayList<String>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.channels_list_layout, container, false);
final ListView channelsList = (ListView) rootView.findViewById(R.id.channelsListView);
String[] chNames = new String[]{"ChA","ChB","ChC"};
final ArrayList<String> list = new ArrayList<String>();
for (int i = 0; i < chNames.length; ++i) {
list.add(chNames[i]);
}
//set adapter to listview
MyListAdapter listAdapter = new MyListAdapter(getActivity(),chNames);
channelsList.setAdapter(listAdapter);
return rootView;
}
public interface FavButtonClickedListener {
public void onFavButtonClicked(int position,List<String>favs);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
context = getActivity();
// This makes sure that the container activity has implemented
// the callback interface. If not, it throws an exception
try {
whenFavButtonClicked = (FavButtonClickedListener)context;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnHeadlineSelectedListener");
}
}
}
ChannelsFragment Adapter类：
public class MyListAdapter extends ArrayAdapter<String>{
private final Context context;
private final String[] values;
URL channelUrl;
public MyListAdapter(Context context, String[] values) {
super(context, R.layout.list_item_complex, values);
this.context = context;
this.values = values;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
public long getCount(int position) {
// TODO Auto-generated method stub
return values.length;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.list_item_complex, parent, false);
TextView chNameText = (TextView) rowView.findViewById(R.id.chName);
ImageView imageView = (ImageView) rowView.findViewById(R.id.chImage);
final ImageButton imageButton = (ImageButton)rowView.findViewById(R.id.starButon);
Button chButton = (Button)rowView.findViewById(R.id.chButon);
chNameText.setText(values[position]);
//Set the channels' logo appropriately
if(values[position].equals("CHa")){
imageView.setImageResource(R.drawable.CHaImage);
imageButton.setId(0);
}else if(values[position].equals("CHb")){
imageView.setImageResource(R.drawable.CHbImage);
imageButton.setId(1);
}else if(values[position].equals("Chc")){
imageView.setImageResource(R.drawable.CHcImage);
imageButton.setId(2);
}else{
imageView.setImageResource(R.drawable.defult_bacground_logo);
}
}
//Determine the target url for each channel correctly
chButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent("android.intent.action.Activity2");
String chName = null;
if(values[position].equals("CHa")){
i.putExtra("CHa", "http://www.cha.com/");
chName = "CHa";
i.putExtra("nameofCh", ChName);
startActivity(i);
}
if(values[position].equals("CHb")){
i.putExtra("CHb", "http://www.chb.com/");
chName = "CHb";
i.putExtra("nameofCh",ChName);
startActivity(i);
}
if(values[position].equals("CHc")){
i.putExtra("CHc", "http://www.chc.com/");
chName = "CHc";
i.putExtra("nameofCh",ChName);
startActivity(i);
}
});
final Context konteks;
konteks = this.getContext();
//set button click for favorite channels list
// I use this imageButton for create a favorites list in listview in FavoritesChannels
//fragment. I want when the user click this button, the row that has been clicked, get
//passed to FavoritesChannels fragment
imageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
imageButton.setImageResource(R.drawable.button_states_star);
SharedPreferences prefs = konteks.getSharedPreferences("favorites",Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
if(imageButton.getId()==0){
editor.putBoolean("CHaChecked", true);
editor.commit();
favValues.add("CHa");
whenFavButtonClicked.onFavButtonClicked(position,favValues);
Toast.makeText(getActivity(), "CHa have been added to favlist", Toast.LENGTH_SHORT).show();
}
else if(imageButton.getId()==1){
editor.putBoolean("CHbChecked", true);
favValues.add("CHb");
editor.commit();
whenFavButtonClicked.onFavButtonClicked(position,favValues);
Toast.makeText(getActivity(), "CHb have been added to favlist", Toast.LENGTH_SHORT).show();
}
else if(imageButton.getId()==2){
editor.putBoolean("CHcChecked", true);
favValues.add("CHc");
editor.commit();
whenFavButtonClicked.onFavButtonClicked(position,favValues);
Toast.makeText(getActivity(), "CHc have been added to favlist", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(getActivity(), "CH have been added to favlist", Toast.LENGTH_SHORT).show();
}
}
});
return rowView;
}
}
MainActivity.java：
onFavButtonClicked（）实现位于文件末尾
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener,KanallarFragment.FavButtonClickedListener {
private static final int NUM_PAGES = 2;
public SharedPreferences prefs;
FragmentTransaction fragmentTransaction;
/**
* The pager widget, which handles animation and allows swiping horizontally to access previous
* and next wizard steps.
*/
private ViewPager mPager;
/**
* The pager adapter, which provides the pages to the view pager widget.
*/
private PagerAdapter mPagerAdapter;
//Initiate Actionbar instance and define its tab names
private ActionBar actionBar;
private String[] tabs = { "Channels", "Favorites"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragMgr = getSupportFragmentManager();
fragmentTransaction = fragMgr.beginTransaction();
fragmentTransaction.add(new FavoriteFragment(), "favsFragment");
fragmentTransaction.add(new ChannelsFragment(), "channelsFragment");
// Instantiate a ViewPager and a PagerAdapter.
mPager = (ViewPager) findViewById(R.id.pager);
mPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
//ViewPager's PageChangeListener
mPager.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) {
}
});
//Retrieve actionbar and set some properties
actionBar = getSupportActionBar();
//actionBar.setHomeButtonEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setStackedBackgroundDrawable(getResources().getDrawable(R.drawable.actionbar_gradient));
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(true);
// Adding Tabs to actionbar
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name).setTabListener(this));
}
for(int i = 0; i<actionBar.getTabCount(); i++){
LayoutInflater inflater = LayoutInflater.from(this);
View customView = inflater.inflate(R.layout.tab_layout, null);
TextView titleTV = (TextView) customView.findViewById(R.id.action_custom_title);
titleTV.setText(tabs[i]);
ImageView tabImage = (ImageView)customView.findViewById(R.id.tab_icon);
if(i==0){
tabImage.setImageResource(R.drawable.television_icon_64);
}else{
tabImage.setImageResource(R.drawable.star_icon);
}
actionBar.getTabAt(i).setCustomView(customView);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/*public void onTabSelected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
mPager.setCurrentItem(tab.getPosition());
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// TODO Auto-generated method stub
}*/
private class ViewPagerAdapter extends FragmentStatePagerAdapter {
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new ChannelsFragment();
case 1:
return new FavoritesFragment();
}
return null;
}
@Override
public int getCount() {
return NUM_PAGES;
}
}
@Override
public void onTabReselected(Tab arg0,FragmentTransaction arg1) {
// TODO Auto-generated method stub
}
@Override
public void onTabSelected(Tab arg0,FragmentTransaction arg1) {
// TODO Auto-generated method stub
mPager.setCurrentItem(arg0.getPosition());
}
@Override
public void onTabUnselected(Tab arg0,FragmentTransaction arg1) {
// TODO Auto-generated method stub
}
public void onFavButtonClicked(int position,List<String>favs) {
// TODO Auto-generated method stub
FavoritesFragment favFrag = (FavoritesFragment)getSupportFragmentManager().findFragmentByTag("favsFragment");
if(favFrag !=null){
favFrag.updateList(position,favs);
}
}
包含updateList（）方法的FavoritesFragment类：
public class FavorilerFragment extends Fragment {
Context context;
private final List<String> values = new ArrayList<String>();
private final List<String> favValues = new ArrayList<String>();
ListView listView;
TextView textView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Context context = getActivity();
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.favorites_list_layout, container, false);
listView = (ListView)rootView.findViewById(R.id.f_channels_ListView);
textView = (TextView)rootView.findViewById(R.id.favListMessage);
SharedPreferences prefs = context.getSharedPreferences("favorites",getActivity().MODE_PRIVATE);
//-----SharedPreferences values for adapter----
if(prefs.getBoolean("CHaChecked", false)){
values.add("Cha");
}
if(prefs.getBoolean("CHbChecked", false)){
values.add("Chb");
}
if(prefs.getBoolean("ChcChecked", false)){
values.add("Chc");
}
//-----------------------------------------------
if(values.size() == 0){
textView.setText("Favorites List is empty");
}else{
textView.setText("");
}
MyListAdapter adapter = new MyListAdapter(getActivity(),values);
listView.setAdapter(adapter);
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
context = getActivity();
}
public void updateList(int position,List<String> argfavValues){
for(int a= 0;a<argFavValues.size();a++){
favValues.add(argFavValues.get(a));
}
MyListAdapter = new MyListAdapter(getActivity(),favValues);
adaptor.notifyDataSetChanged();
listView.setAdapter(adapter);
}
public static class MyListAdapter extends ArrayAdapter<String>{
private final Context context;
private final List<String> values = new ArrayList<String>();
URL ChUrl;
public MyListAdapter(Context context, List<String> values) {
super(context, R.layout.list_item_complex_fav, values);
this.context = context;
for(int i=0;i<values.size();i++){
this.values.add(values.get(i));
}
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
public long getCount(int position) {
// TODO Auto-generated method stub
return values.size();
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.list_item_complex_fav, parent, false);
TextView chNameText = (TextView) rowView.findViewById(R.id.ChName);
ImageView imageView = (ImageView) rowView.findViewById(R.id.ChannelsImage);
Button chButton = (Button)rowView.findViewById(R.id.chButon);
chNameText.setText(values.get(position));
//Set the channels' logo appropriately
if(values.get(position).equals("CHa")){
imageView.setImageResource(R.drawable.CHaImage);
}else if(values.get(position).equals("CHb")){
imageView.setImageResource(R.drawable.CHbImage);
}else if(values.get(position).equals("CHc")){
imageView.setImageResource(R.drawable.CHcImage);
else{
imageView.setImageResource(R.drawable.default_logo);
}
return rowView;
}
}
答案 0 :(得分：0)
根据官方documentation，片段到片段的通信应该通过活动路由。
您需要在channel片段中创建一个接口，并定义一些回调方法，如onSelected。选择列表项后，使用活动上下文调用该接口方法：
public class ChannelsFragment extends ListFragment {
OnItemSelectedListener mCallback;
public interface OnItemSelectedListener {
public void onSelected(int position);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallback = (OnItemSelectedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnItemSelectedListener");
}
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
mCallback.onSelected(position);
}
}
然后，您的活动需要 implement ChannelFragment.OnItemSelectedListener 并定义回调方法。
public void onSelected(int position) {
Fragment2 fragment = (Fragment2)
getSupportFragmentManager().findFragmentById(R.id.fragment2);
if (fragment != null) {
fragment.updateValue(position);
}
}
您可以通过参数传递数据。要将数据发送到另一个片段，请在片段中创建一个可以直接从活动调用的公共方法。