androidfragmentpageradaptergetstring

Why am I getting getString error? And how to resolve?


I am testing out the FragmentPagerAdapter and I had it all in a single class before. And everything worked, but once I separated SectionsPagerAdapter class, the getString doesn't work under the getPageTitle function.

I know getPageTitle is part of the PagerAdapter class, but I want to know what the best way to have that function included in this class. Do I need to extend the class?

SectionsPageAdapter class

import java.util.Locale;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

// A FragmentPagerAdapter that returns a fragment corresponding to one of the sections/tabs/pages. 
public class SectionsPagerAdapter extends FragmentPagerAdapter {

public SectionsPagerAdapter(FragmentManager fm) {
    super(fm);
}

@Override  
public Fragment getItem(int position) {  
    // getItem is called to instantiate the fragment for the given page.  
    // Return a DummySectionFragment (defined as a static inner class  
    // below) with the page number as its lone argument.  
    Fragment fragment = new DummySectionFragment();  
    Bundle args = new Bundle();  
    args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);  
    fragment.setArguments(args);  
    return fragment;
}

@Override
public CharSequence getPageTitle(int position) {  
    Locale l = Locale.getDefault();  
    switch (position) {  
    case 0:  
        return getString(R.string.myFriendsTab).toUpperCase(l);  
    case 1:
        return getString(R.string.myDealsTab).toUpperCase(l);  
    case 2:
        return getString(R.string.featuredDealsTab).toUpperCase(l);
    case 3:
        return getString(R.string.browseCategoriesTab).toUpperCase(l);  
    case 4:
        return getString(R.string.localDealsTab).toUpperCase(l);  
    }  
    return null;  
}

@Override  
public int getCount() {  
     // Show 5 total pages.  
     return 5;  
}
}

MainActivity class

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.Menu;

public class MainActivity extends FragmentActivity {
    // Fragment PagerAdapter keeps every loaded fragment in memory. 
    // If too memory intensive, switch to FragmentStatePagerAdapter.
    SectionsPagerAdapter mSectionsPagerAdapter;

    ViewPager mViewPager; // ViewPager that will host section contents.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Creates the adapter that will return a fragment for each of the primary sections.
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager(), null);

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

Solution

  • getString(int) only works for Classes that have access to a Context - Fragments, Activities, etc.

    Given that this an Adapter class, it won't have direct access to a Context, so you should probably pass one in with the constructor.

    private Context mContext = null;
    
    public SectionsPagerAdapter(FragmentManager fm, Context context) {
        super(fm);
        mContext = context;
    }
    

    and then use the member field to access getString(int)

    return mContext.getString(R.string.myFriendsTab).toUpperCase(1);