Question

这是我的PagerAdapter。

public class SlideAdapter extends PagerAdapter{
    private List<ImageView> views;

    public SlideAdapter (List<ImageView> views){
        this.views=views;
    }

    @Override
    public void destroyItem(View container, int position, Object object) {
        ((ViewPager) container).removeView(views.get(position));
    }

    @Override
    public int getCount() {
        return views.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view==object;
    }

    @Override
    public Object instantiateItem(View container, int position) {
        ((ViewPager) container).addView(views.get(position));
        return views.get(position);
    }

}

这是我的片段。

public class sportfragment extends Fragment {

    private ViewPager slideviewpager;
    private Boolean isContinue=true;
    private AtomicInteger what=new AtomicInteger (0);
    private ImageView[] indiimageview;
    private List<ImageView> pics;

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";


    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public sportfragment() {

    }


    public static sportfragment newInstance(String param1, String param2) {
        sportfragment fragment = new sportfragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view=inflater.inflate(R.layout.fragment_sportfragment, container, false);

        slideviewpager=(ViewPager) view.findViewById(R.id.slideviewpager);
        ViewGroup indicatorgroup=(ViewGroup) view.findViewById(R.id.indicatorgroup);

        pics=new ArrayList<ImageView>();

        ImageView slide1=new ImageView(view.getContext());
        slide1.setBackgroundResource(R.drawable.slide1);
        pics.add(slide1);

        ImageView slide2=new ImageView(view.getContext());
        slide1.setBackgroundResource(R.drawable.slide2);
        pics.add(slide2);

        ImageView slide3=new ImageView(view.getContext());
        slide1.setBackgroundResource(R.drawable.slide3);
        pics.add(slide3);

        ImageView slide4=new ImageView(view.getContext());
        slide1.setBackgroundResource(R.drawable.slide4);
        pics.add(slide4);

        indiimageview=new ImageView[pics.size()];

        for (int i=0;i<pics.size();i++) {
            ImageView buff=new ImageView(view.getContext());
            buff.setLayoutParams(new LinearLayout.LayoutParams(20,20));
            buff.setPadding(5,5,5,5);
            indiimageview[i]=buff;
            if (i==0) {
                indiimageview[i].setBackgroundResource(R.drawable.focus);
            }else {
                indiimageview[i].setBackgroundResource(R.drawable.blur);
            }
            indicatorgroup.addView(indiimageview[i]);
        }

        slideviewpager.setAdapter(new SlideAdapter(pics));
        slideviewpager.setOnPageChangeListener(new GuidePageChangeListener());

        return view;
    }


    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }


    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }


    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }

    private final class GuidePageChangeListener implements ViewPager.OnPageChangeListener{

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

            for (int i=0;i<indiimageview.length;i++) {

                if (i==position) {
                //4 points change with viewpager
                   indiimageview[i].setBackgroundResource(R.drawable.focus);
                } else {
                    indiimageview[i].setBackgroundResource(R.drawable.blur);
                }
            }
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    }
}

首页是图片。但其他3个是空白的。有什么方法可以解决这个问题吗？

Answer 1

ViewPagers旨在与片段一起使用，而不是视图。这意味着您应该将ImageViews打包为碎片而不是普通的旧视图。

考虑以下示例：

MyImageView.java

public class MyImageFragment extends Fragment {

    private ImageView mImageView;
    private int resourceId;

    public static MyImageFragment newInstance(int resourceId) {
        MyImageFragment fragment = new MyImageFragment();

        Bundle args = new Bundle();
        args.putInt("resource_id", resourceId);
        fragment.setArguments(args);

        return fragment;
    }

    @Override
    public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final Bundle args = getArguments();
        if (args != null && !loadedFromArgs) {
            url = (String)args.getSerializable("url");
            resourceId = args.getInt("in_list", -1);
            loadedFromArgs = true;
        }

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(
                R.layout.fragment_my_image, container, false);

        mImageView = (ImageView) rootView.findViewById(R.id.image);
        mImageView.setBackgroundDrawable(getResources().getDrawable(resourceId))
        return rootView;
    }
}

fragment_my_image.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:id="@+id/image"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="fitCenter"
        android:adjustViewBounds="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"/>

</RelativeLayout>

现在，您将拥有一个由PagerAdapter指向的MyImageFragment列表，而不是ImageView列表。

为什么PagerAdapter里面的片段只显示第一个视图？

1 个答案: