问题描述
Adapter
public class AdvViewPagerAdapter extends FragmentPagerAdapter { private Context context; private List<String> urls; private List<ImageView> imgs; private List<Fragment> fragments; public AdvViewPagerAdapter(FragmentManager fm, Context context, List<String> urls) {super(fm);this.context = context;this.urls = urls;// imgs = new ArrayList<ImageView>();fragments = new ArrayList<Fragment>();for (String url : urls) { MyImageFragment fragment = new MyImageFragment(context, url); fragments.add(fragment);} } @Override public int getCount() {return urls.size(); } @Override public boolean isViewFromObject(View view, Object object) {return view == object; } @Override public Fragment getItem(int position) {MLog.i(fragments.get(position));return fragments.get(position); }}
Fragment
class MyImageFragment extends BaseFragment {private View view;private ImageView mImageView;private String url;public MyImageFragment(Context context, String url) { super(context); this.url = url;}@Overridepublic View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { view = getLayout(inflater, container, R.layout.image_layout, false); initView(); Picasso.with(getContext()).load(url).into(mImageView); return view;}@Overridepublic void initView() { mImageView = (ImageView) view.findViewById(R.id.image_layout_iv);} }
R.layout.image_layout
<LinearLayoutandroid:layout_width='match_parent'android:layout_height='match_parent' ><ImageView android: android:layout_width='match_parent' android:layout_height='match_parent' android:background='@color/dark_gray' /> </LinearLayout>
Test代码
public class WelcomeActivity extends BaseActivity { private ViewPager viewpager; @Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_welcome);initView(); } @Override public void initView() {viewpager = (ViewPager) findViewById(R.id.viewpager);List<String> urls = new ArrayList<String>();urls.add('http://hiphotos.baidu.com/baidu/pic/item/4ec2d5628535e5dd3c10363671c6a7efce1b621f.png');urls.add('http://hiphotos.baidu.com/baidu/pic/item/a8ec8a13632762d07842064fa6ec08fa503dc6c6.png');urls.add('http://fanyi.baidu.com/static/translation/img/footer/app_e8ff780.png');viewpager.setAdapter(new AdvViewPagerAdapter(getSupportFragmentManager(), getContext(), urls)); }}
！BaseActivity 继承自 android.support.v4.app.FragmentActivity
！BaseFragment 继承自 android.support.v4.app.Fragment
问题解答
回答1：该问题已关闭_(:3」∠)_
回答2：Fragment不是不建议有参的构造吗？另外毕加索的用法是，尽量定出长宽，如果不定的话用自动适配，比如：
Picasso.with(context) .load(url) .placeholder(res_holder) .error(res_holder) .config(Bitmap.Config.RGB_565) .fit() .centerInside() .into(view);
建议Picasso尽量设置详细点，有助于显示和控制。如果你说的空白，就是说连imageView的背景都没显示的话，还需查看Acitivty里面的代码，看是否是设置有问题。
回答3：你的initView()方法在父类BaseFragment中有调用吗？还是单纯的抽象？在fragment中，context最好使用getActivity()来获取，会对Picasso友好一些，即Picasso.with(getActivity())，可以先试一下。
回答4：fragmentment没复写getItem（）所以得不到子每个pager需要加载的fragment。
