How to get List> with this keyword?

问题:

I have fragment where I get the string in List and send it as Bundle to the activity. For Example I get a string and and send it to an activity by following way:

public class ViewPagerAdapter extends FragmentStatePagerAdapter
{
  private CharSequence contentTitle[];

  public ViewPagerAdapter(Response<album> response)
  {
     List<String> listcontentTitle = new ArrayList<>();
     List<List<String>> latest_list = new ArrayList<>();      
     List<String> latestdate = new ArrayList<>();
     List<String> latestcomment = new ArrayList<>();
     for (int i = 0; i < 5; i++) 
     {
        listcontentTitle.add(String.valueOf(response.body().getcontent().get(i).getcontentTitle()));
        latestdate.add(String.valueOf(response.body().getcontent().get(i).getcontentdate()));
        latestcomment.add(String.valueOf(response.body().getcontent().get(i).getcontentcmnt()));
     }
     latest_list.add(latestdate);
     latest_list.add(latestcomment);
     this.contentTitle = listcontentTitle.toArray(new CharSequence[listcontentTitle.size()]);
     // (1) access latest_list with this keyword
  }

  @Override
  public Fragment getItem(int position)
  {
    Fragment Detail=new Detail(mContext);
    Bundle bundle= new Bundle();
    bundle.putString("content_title",contentTitle[position].toString());
    // (2) pass the latest list in bundle
    Detail.setArguments(bundle);
    return Detail;
  }
}

Now what should be my (1) and (2) in order to access latest_list and pass it in bundle?

回答1:

1) You cannot use this here. Set it as a private right above the method, like this:

public class ViewPagerAdapter extends FragmentStatePagerAdapter
{
    private CharSequence contentTitle[];
    private List<List<String>> latestList; // This let's you use latestList outside of this ViewPagerAdapter class.
    public ViewPagerAdapter(Response<album> response)
    {
        List<String> listcontentTitle = new ArrayList<>();
        List<List<String>> latest_list = new ArrayList<>();      
        List<String> latestdate = new ArrayList<>();
        List<String> latestcomment = new ArrayList<>();
        for (int i = 0; i < 5; i++) 
        {
            listcontentTitle.add(String.valueOf(response.body().getcontent().get(i).getcontentTitle()));
            latestdate.add(String.valueOf(response.body().getcontent().get(i).getcontentdate()));
            latestcomment.add(String.valueOf(response.body().getcontent().get(i).getcontentcmnt()));
        }
        latest_list.add(latestdate);
        latest_list.add(latestcomment);
        contentTitle = listcontentTitle.toArray(new CharSequence[listcontentTitle.size()]);
        lastestList = lastest_list;
    }
    public List<List<String>> getLatestList(){
        return latestList;
    }

You can now use latestList in another class like this:

ViewPageAdapter viewpage = new ViewPageAdapter(response);
List<List<String>> latest_list = viewpage.getLatestList();

For passing a list using bundles, look at this answer: https://stackoverflow.com/a/28197436/4561008

You'll need to use implements Parcelable in your ViewPageAdapter declaration.