我在MainActivity中有一个变量，我已成功传递给StoriesActivity。
问题在于从那里到StoriesFragment，这是TabLayout标签。
我了解Intents和Bundles但我不确定它们在这种情况下是如何工作的。
这是StoriesActivity：
public class StoriesActivity extends AppCompatActivity {
//This is our tablayout
private TabLayout tabLayout;
//This is our viewPager
private ViewPager viewPager;
private Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_stories);
/* +++ START Intent +++ */
Bundle extras = getIntent().getExtras();
final int authorID = extras.getInt("author_id");
final String authorName = extras.getString("author_name");
Log.i("click", Integer.toString(authorID));
// this is successful
/* +++ END Intent +++ */
toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle(authorName);
setSupportActionBar(toolbar);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new StoriesFragment(), "Stories");
adapter.addFragment(new CollectionsFragment(), "Collections");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
这就是StoriesFragment（目前无效，因为它没有从StoriesActivity访问authorID变量）：
public class StoriesFragment extends Fragment {
public StoriesFragment() {
// Required empty public constructor
}
private ListView storiesListView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// link ListView object with XML ListView
storiesListView = (ListView) findViewById(R.id.stories_list_view);
// create new instance of DatabaseHelper
DatabaseHelper db = new DatabaseHelper(this);
// create list of stories through getAllStories method
List<Book> storyList = db.getAllStories(authorID);
// create new ArrayAdapter
ArrayAdapter<Book> arrayAdapter =
new ArrayAdapter<Book>(this, android.R.layout.simple_list_item_1, storyList);
// link ListView and ArrayAdapter
storiesListView.setAdapter(arrayAdapter);
Log.i("test", storyList.toString());
storiesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Book story = (Book) storiesListView.getItemAtPosition(i);
//Log.i("click", story);
Intent intent = new Intent(StoriesActivity.this, StoryBodyActivity.class);
intent.putExtra("story", story.getTitle());
startActivity(intent);
//Log.i("click", "That's a click!");
}
});
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_stories, container, false);
}
}
StoriesTabsAdapter：
public class StoriesTabsAdapter extends FragmentPagerAdapter {
int mNumOfTabs;
public StoriesTabsAdapter(FragmentManager fm, int NumOfTabs) {
super(fm);
this.mNumOfTabs = NumOfTabs;
}
private String[] tabTitles = new String[]{"Stories", "Collections"};
// overriding getPageTitle()
@Override
public CharSequence getPageTitle(int position) {
return tabTitles[position];
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
StoriesFragment tab1 = new StoriesFragment();
return tab1;
case 1:
CollectionsFragment tab2 = new CollectionsFragment();
return tab2;
default:
return null;
}
}
@Override
public int getCount() {
return tabTitles.length;
}
}
答案 0 :(得分：1)
以下是您问题的解决方案：
这是你的活动：
public class StoriesActivity extends AppCompatActivity {
//This is our tablayout
private TabLayout tabLayout;
//This is our viewPager
private ViewPager viewPager;
private Toolbar toolbar;
private int authorID;
private String authorName;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_stories);
/* +++ START Intent +++ */
Bundle extras = getIntent().getExtras();
authorID = extras.getInt("author_id");
authorName = extras.getString("author_name");
Log.i("click", Integer.toString(authorID));
// this is successful
/* +++ END Intent +++ */
toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle(authorName);
setSupportActionBar(toolbar);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(StoriesFragment.newInstance(authorID, authorName), "Stories");
adapter.addFragment(new CollectionsFragment(), "Collections");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
这是你的片段：
public class StoriesFragment extends Fragment {
private int authorID;
private String authorName;
public StoriesFragment() {
// Required empty public constructor
}
public static StoriesFragment newInstance(int authorID, String authorName) {
Bundle args = new Bundle();
args.putInt("author_id", authorID);
args.putString("author_name", authorName);
StoriesFragment fragment = new StoriesFragment();
fragment.setArguments(args);
return fragment;
}
private ListView storiesListView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Here is your arguments
authorID = getArguments().getInt("author_id");
authorName = getArguments().getString("author_name");
// link ListView object with XML ListView
storiesListView = (ListView) findViewById(R.id.stories_list_view);
// create new instance of DatabaseHelper
DatabaseHelper db = new DatabaseHelper(this);
// create list of stories through getAllStories method
List<Book> storyList = db.getAllStories(authorID);
// create new ArrayAdapter
ArrayAdapter<Book> arrayAdapter =
new ArrayAdapter<Book>(this, android.R.layout.simple_list_item_1, storyList);
// link ListView and ArrayAdapter
storiesListView.setAdapter(arrayAdapter);
Log.i("test", storyList.toString());
storiesListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Book story = (Book) storiesListView.getItemAtPosition(i);
//Log.i("click", story);
Intent intent = new Intent(StoriesActivity.this, StoryBodyActivity.class);
intent.putExtra("story", story.getTitle());
startActivity(intent);
//Log.i("click", "That's a click!");
}
});
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_stories, container, false);
}
}
希望它会对你有所帮助。
答案 1 :(得分：0)
从StoriesActivity发送捆绑数据
private void setupViewPager(ViewPager viewPager) {
Bundle bundle = new Bundle();
bundle.putString("your_key", "yourdata");
// set Fragmentclass Arguments
StoriesFragment fragStory = new StoriesFragment();
fragStory.setArguments(bundle);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(fragStory, "Stories");
adapter.addFragment(new CollectionsFragment(), "Collections");
viewPager.setAdapter(adapter);
}