在ViewPager片段中添加通过bundle的hashmap

Question

我正在使用带有片段的view-pager，并通过捆绑式实例将哈希映射传递到片段。但是它并未在View-Pager中显示所有图像，默认情况下只显示第三张图像。我对此感到困惑...任何帮助都会明显。以下是我的Java代码

public class MainActivity extends AppCompatActivity {
    ViewPager viewPager;
    List<Fragment> fragments1;
    public MyPagerAdapter adapter1;
    static final ArrayList<HashMap<String, Integer>> list = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        viewPager = (ViewPager) findViewById(R.id.pager1);
        fragments1 = getFragments1();
        adapter1 = new MyPagerAdapter(getSupportFragmentManager(), fragments1);
        viewPager.setAdapter(adapter1);
    }

    public class MyPagerAdapter extends FragmentPagerAdapter {
        private List<Fragment> fragments;
        public MyPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
            super(fm);
            this.fragments = fragments;
        }
        @Override
        public Fragment getItem(int position) {
            return this.fragments.get(position);
        }
        @Override
        public int getCount() {
            return this.fragments.size();
        }
        @Override
        public int getItemPosition (Object object)
        {
            if (object instanceof MyImageSlider ) {
                return POSITION_NONE;
            }
            return POSITION_UNCHANGED;
        }
   }
    private List<Fragment> getFragments1() {
        List<Fragment> fList = new ArrayList<>();
        for(int i = 0; i < 5; i++){
            HashMap<String, Integer> map = new HashMap<>();
            map.put("0",R.drawable.first);
            map.put("1",R.drawable.second);
            map.put("2",R.drawable.three);
            map.put("3",R.drawable.four);
            map.put("4",R.drawable.xiaomi);
            list.add(map);
            fList.add(MyImageSlider.newInstance(list.get(i)));
        }
       return fList;
    }
    public static class MyImageSlider extends Fragment {
        HashMap<String, Integer> imageid;
        ArrayList<HashMap<String, Integer>> listArray = new ArrayList<>();
        public static MyImageSlider newInstance(HashMap<String, Integer> id)
        {

            MyImageSlider slider=new MyImageSlider();
            Bundle b=new Bundle();
            b.putSerializable("imageid", id);
            slider.setArguments(b);
            return slider;
        }
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            imageid=(HashMap<String, Integer>) getArguments().getSerializable("imageid");
            listArray.add(imageid);
        }
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.content_main, container, false);
            ImageView iv=(ImageView)view.findViewById(R.id.img);
           for (String key : imageid.keySet()) {
               iv.setImageResource(imageid.get(key);
            }  

            return view;
        }
    }
 }

Answer 1

为什么要创建片段列表，您可以创建一个单个片段，该片段持有图像视图并通过适配器传递图像列表，并在该片段上显示图像。

请检查下面的代码 - 让我知道您是否有任何担忧。

//这是您的MainActivity.java

package com.sample.stack;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
    ViewPager viewPager;

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

        viewPager = (ViewPager) findViewById(R.id.pager1);
        HashMap<String,Integer> sliderDataList = new HashMap<String,Integer>();
        sliderDataList.put("0",R.drawable.tc);
        sliderDataList.put("1",R.drawable.tc);
        sliderDataList.put("2",R.drawable.tc);
        sliderDataList.put("3",R.drawable.tc);
        sliderDataList.put("4",R.drawable.tc);
        PagerAdapter adapter1 = new PagerAdapter(getSupportFragmentManager(), sliderDataList, MainActivity.this);
        viewPager.setAdapter(adapter1);
    }
}

//这是您的FragmentPagerAdapter

package com.sample.stack;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import java.util.HashMap;
/**
 * Created by on 06-12-2016.
 */
public class PagerAdapter extends FragmentPagerAdapter {
    private final HashMap<String, Integer> hMap;
    private final Context context;
    public PagerAdapter(FragmentManager fm, HashMap<String,Integer> hMap, Context context) {
        super(fm);
        this.hMap=hMap;
        this.context=context;
    }
    @Override
    public Fragment getItem(int position) {
        return new SliderFragment(hMap,context,position);
    }
    @Override
    public int getCount() {
        return hMap.size();
    }
}

//这是您的碎片containg imageView

package com.sample.stack;
import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import java.util.ArrayList;
import java.util.HashMap;
/**
 * Created by Syscraft on 06-12-2016.
 */
@SuppressLint("ValidFragment")
public class SliderFragment extends Fragment {
    private final HashMap<String, Integer> urls;
    private int imageResourceId;
    private Context ctx;
    public SliderFragment(HashMap<String,Integer> urls, Context c,
                          int pos) {
        this.urls = urls;
        this.imageResourceId = pos;
        this.ctx = c;
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.slider_adapter, container, false);
        final ImageView imageView = (ImageView) view
                .findViewById(R.id.sliderImages);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
       imageView.setImageResource(urls.get(imageResourceId+""));
        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
            }
        });
        return view;
    }
}

Answer 2

公共类MainActivity扩展了AppCompatactivity {

ViewPager viewPager;

公共pageradapter adapter1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    viewPager = (ViewPager) findViewById(R.id.pager1);
    final HashMap<String,Integer> sliderDataList = new HashMap<String,Integer>();
    sliderDataList.put("0",R.drawable.first);
    sliderDataList.put("1",R.drawable.second);
    sliderDataList.put("2",R.drawable.three);
    sliderDataList.put("3",R.drawable.four);
    sliderDataList.put("4",R.drawable.xiaomi);
     adapter1 = new PagerAdapter(getSupportFragmentManager(), sliderDataList, MainActivity.this);
    viewPager.setAdapter(adapter1);
  //  sliderDataList.remove("3");
    adapter1.notifyDataSetChanged();
    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }
        @Override
        public void onPageSelected(int position) {
          remove("3");
        }
        @Override
        public void onPageScrollStateChanged(int state) {
        }
    });
}
public void remove(String s){
    adapter1.remove(s);
}
public class PagerAdapter extends FragmentPagerAdapter {
    private final HashMap<String, Integer> hMap;
    private final Context context;
    public PagerAdapter(FragmentManager fm, HashMap<String,Integer> hMap, Context context) {
        super(fm);
        this.hMap=hMap;
        this.context=context;
    }
    @Override
    public Fragment getItem(int position) {
        return new SliderFragment(hMap,context,position);
    }
    @Override
    public int getCount() {
        return hMap.size();
    }
    public void remove(String s){
        Iterator<Map.Entry<String,Integer>> iter = hMap.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry<String,Integer> entry = iter.next();
            if(s.equalsIgnoreCase(entry.getKey())){
                iter.remove();
            }
        }
        hMap.remove(s);
        adapter1.notifyDataSetChanged();
    }
}
@SuppressLint("ValidFragment")
public static class SliderFragment extends Fragment {
    private final HashMap<String, Integer> urls;
    private int imageResourceId;
    private Context ctx;
    public SliderFragment(HashMap<String,Integer> urls, Context c, int pos) {
        this.urls = urls;
        this.imageResourceId = pos;
        this.ctx = c;
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.content_main, container, false);
        final ImageView imageView = (ImageView) view
                .findViewById(R.id.img);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setImageResource(urls.get(imageResourceId +""));
        return view;
    }
}

}