보기 페이지 수정?

Question

나는 안드로이드에 좀 새로운있어, 안드로이드 스튜디오의 기본보기 호출기를 사용자 정의하려고합니다. . 내가보기 호출기의 페이지 번호를 얻으려고하고 예를 들어 각 페이지마다 다른 이미지를 설정하려고합니다.

package blabla.example.com.bla; 

import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.support.v7.app.AppCompatActivity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.TextView; 


public class MainActivity extends AppCompatActivity { 

    /** 
    * The {@link android.support.v4.view.PagerAdapter} that will provide 
    * fragments for each of the sections. We use a 
    * {@link FragmentPagerAdapter} derivative, which will keep every 
    * loaded fragment in memory. If this becomes too memory intensive, it 
    * may be best to switch to a 
    * {@link android.support.v4.app.FragmentStatePagerAdapter}. 
    */ 
    private SectionsPagerAdapter mSectionsPagerAdapter; 

    /** 
    * The {@link ViewPager} that will host the section contents. 
    */ 
    private ViewPager mViewPager; 

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


     // Create the adapter that will return a fragment for each of the three 
     // primary sections of the activity. 
     mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); 

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

    } 



    /** 
    * A placeholder fragment containing a simple view. 
    */ 
    public static class PlaceholderFragment extends Fragment { 
     /** 
     * The fragment argument representing the section number for this 
     * fragment. 
     */ 
     private static final String ARG_SECTION_NUMBER = "section_number"; 

     public PlaceholderFragment() { 
     } 

     /** 
     * Returns a new instance of this fragment for the given section 
     * number. 
     */ 
     public static PlaceholderFragment newInstance(int sectionNumber) { 
      PlaceholderFragment fragment = new PlaceholderFragment(); 
      Bundle args = new Bundle(); 
      args.putInt(ARG_SECTION_NUMBER, sectionNumber); 
      fragment.setArguments(args); 
      return fragment; 



    } 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 
      View rootView = inflater.inflate(R.layout.fragment_main, container, false); 
      TextView textView = (TextView) rootView.findViewById(R.id.section_label); 
      textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER))); 


      ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); 

      if (!ARG_SECTION_NUMBER.equals("1")) { 
       levelImage.setImageResource(R.drawable.example1); 
      } 
      else if (!ARG_SECTION_NUMBER.equals("2")) { 
       levelImage.setImageResource(R.drawable.example2); 
      } 
      else if (!ARG_SECTION_NUMBER.equals("3")) { 
       levelImage.setImageResource(R.drawable.example3); 
      } 
      else if (!ARG_SECTION_NUMBER.equals("4")) { 
       levelImage.setImageResource(R.drawable.example4); 
      } 
      else { 
       levelImage.setImageResource(R.drawable.example5); 
      } 




      return rootView; 

     } 
    } 

    /** 
    * A {@link 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 PlaceholderFragment (defined as a static inner class below). 
      return PlaceholderFragment.newInstance(position + 1); 
     } 

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

     @Override 
     public CharSequence getPageTitle(int position) { 
      switch (position) { 
       case 0: 
        return "SECTION 1"; 
       case 1: 
        return "SECTION 2"; 
       case 2: 
        return "SECTION 3"; 
       case 3: 
        return "SECTION 4"; 
       case 4: 
        return "SECTION 5"; 
      } 
      return null; 
     } 


    } 
} 

당신은) 내가 지금까지 :)이 시도

ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); 

     if (!ARG_SECTION_NUMBER.equals("1")) { 
      levelImage.setImageResource(R.drawable.example51); 
     } 
     else if (!ARG_SECTION_NUMBER.equals("2")) { 
      levelImage.setImageResource(R.drawable.example2); 
     } 
     else if (!ARG_SECTION_NUMBER.equals("3")) { 
      levelImage.setImageResource(R.drawable.example3); 
     } 
     else if (!ARG_SECTION_NUMBER.equals("4")) { 
      levelImage.setImageResource(R.drawable.example4); 
     } 
     else { 
      levelImage.setImageResource(R.drawable.example5); 
     } 

를 볼 수 있지만 작동하지 않습니다한다. 그래서 내가해야합니까?

Answer 1

변수 ARG_SECTION_NUMBER은 번들의 값을 찾기 위해 키로 사용하는 String을 보유합니다. 그래서 당신은 아마 이렇게 될 코드를 변경해야합니다

물론

if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) { 
    ... 
} 
else if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) { 
    ... 
} 

, 더 나은 솔루션을 직접 번들로 이미지 리소스 ID를 넣어하는 것이 아니라 그냥 섹션 번호를 넣고 다음 만들 것 거대한 if/else 트리. 이 같은 것 :