我有一个问题，我真的找不到是什么原因造成的。
我有一个具有 4 种项目类型的 ListView（getViewTypeCount() 返回 4）。视图类型 0、1 和 3 运行良好。但是，View type 2 的问题是，只绘制了一些 type 2 的项目。表示类型 2 的 View 是 ViewPager。
绘制的 ViewPager 可以完美地工作。未绘制的 ViewPager 仅显示为白色。当我尝试滚动浏览该 ViewPager 时，它会在侧面显示蓝色光晕，表明您位于第一页或最后一页。每次的页数都是正确的。
ViewPager 包含一个 NormalSectionFragment，ViewPager 的其余部分是每个页面上都有一张照片的页面 PhotoSectionFragment。
有几件事我很确定：
- ViewPager中Fragments的onCreateView方法在每次ViewPager出现（或应该出现）时被调用
- 当我一直向下滚动并向后滚动时，每个 ViewPager 都被绘制并完美运行
我可以通过以编程方式向下和向上滚动来解决它，但我认为这不是解决它的正确方法。
getItemViewType 方法：
@Override
public int getItemViewType(int position) {
NieuwsItem item = getItem(position);
if (item instanceof NormalNieuwsItem)
return VIEW_TYPE_NORMAL;
else
if (item instanceof TeaserNieuwsItem)
return VIEW_TYPE_TEASER;
else
return ((FacebookNieuwsItem) item).isPhoto() ? VIEW_TYPE_FACEBOOK_PHOTO : VIEW_TYPE_FACEBOOK;
}
这是列表适配器的 getView() 方法：
@Override
public View getView(int position, View convertView, ViewGroup parent) {
NieuwsItem item = getItem(position);
switch (getItemViewType(position)) {
case 0:
if (convertView == null)
convertView = LayoutInflater.from(context).inflate(R.layout.listitem_nieuwsitem, null);
TextView titleView = (TextView) convertView.findViewById(R.id.titleView);
TextView subTitleView = (TextView) convertView.findViewById(R.id.subTitleView);
titleView.setText(item.getTitle());
subTitleView.setText(item.getSubTitle());
TextView createdAtView = (TextView) convertView.findViewById(R.id.createdAtView);
createdAtView.setText(Tools.getDateString(getContext(), ((NormalNieuwsItem) item).getCreatedAt()));
return convertView;
case 1:
if (convertView == null)
convertView = LayoutInflater.from(context).inflate(R.layout.listitem_teaseritem, null);
TextView teaserTitleView = (TextView) convertView.findViewById(R.id.teaserTitle);
ImageView teaserImageView = (ImageView) convertView.findViewById(R.id.teaserImage);
teaserTitleView.setText(item.getTitle());
Bitmap bmp = ((TeaserNieuwsItem) item).getImage();
if (bmp != null)
teaserImageView.setImageBitmap(bmp);
return convertView;
case 2:
FacebookNieuwsItem fbPhotoItem = (FacebookNieuwsItem) item;
if (convertView == null)
convertView = LayoutInflater.from(context).inflate(R.layout.listitem_facebookitem_photo, null);
ViewPager pager = (ViewPager) convertView.findViewById(R.id.facebookPhotoPager);
PhotoPagerAdapter adapter = new PhotoPagerAdapter(fm, fbPhotoItem);
pager.setAdapter(adapter);
pager.setPageMargin(-40);
pager.setCurrentItem(0, true);
pager.setOffscreenPageLimit(5);
return convertView;
case 3:
FacebookNieuwsItem fbItem = (FacebookNieuwsItem) item;
convertView = LayoutInflater.from(context).inflate(R.layout.listitem_facebookitem, null);
TextView content = (TextView) convertView.findViewById(R.id.facebook_content);
TextView likeCount = (TextView) convertView.findViewById(R.id.facebook_likecount);
TextView commentCount = (TextView) convertView.findViewById(R.id.facebook_commentcount);
TextView createdAt = (TextView) convertView.findViewById(R.id.facebook_date);
if (fbItem.isPhoto())
content.setText(fbItem.getTitle());
else
content.setText(fbItem.getContent());
likeCount.setText(Integer.toString(fbItem.getLikeCount()));
commentCount.setText(Integer.toString(fbItem.getCommentCount()));
createdAt.setText(Tools.getDateString(getContext(), fbItem.getCreatedAt()));
return convertView;
default:
return null;
}
}
ViewPager 的适配器：
public class PhotoPagerAdapter extends FragmentStatePagerAdapter {
private FacebookNieuwsItem item;
public PhotoPagerAdapter(FragmentManager fm, FacebookNieuwsItem item) {
super(fm);
this.item = item;
}
@Override
public Fragment getItem(int i) {
Fragment fragment;
if (i == 0)
fragment = NormalSectionFragment.newInstance(item);
else {
String url = Tools.PHOTO_URL_PREFIX + item.getPhoto(i - 1) + Tools.PHOTO_URL_SUFFIX;
fragment = PhotoSectionFragment.newInstance(url);
}
return fragment;
}
@Override
public CharSequence getPageTitle(int position) {
return Integer.toString(position);
}
@Override
public int getCount() {
return item.getPhotoCount() + 1;
}
}
PhotoSectionFragment：
public static class PhotoSectionFragment extends Fragment {
private ImageView image;
private String url;
public static PhotoSectionFragment newInstance(String url) {
PhotoSectionFragment fragment = new PhotoSectionFragment();
fragment.setUrl(url);
return fragment;
}
private void setUrl(String url) {
this.url = url;
}
public String getUrl() {
return url;
}
public PhotoSectionFragment() {
}
public void setImage(Bitmap bmp) {
Bitmap scaled = Bitmap.createScaledBitmap(bmp, 100, 60, true);
bmp.recycle();
image.setImageBitmap(scaled);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Log.d("photo_oncreateview_start", "url: " + url);
View view = inflater.inflate(R.layout.fb_photo_item, null);
image = (ImageView) view.findViewById(R.id.facebookPhoto);
return view;
}
}
正常部分片段：
public static class NormalSectionFragment extends Fragment {
private FacebookNieuwsItem item;
public NormalSectionFragment() {
}
public static NormalSectionFragment newInstance(FacebookNieuwsItem item) {
NormalSectionFragment section = new NormalSectionFragment();
section.setItem(item);
return section;
}
private void setItem(FacebookNieuwsItem item) {
this.item = item;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Log.d("reg_oncreateview_start", item.getTitle());
View view = inflater.inflate(R.layout.listitem_facebookitem_viewpager, null);
TextView content = (TextView) view.findViewById(R.id.facebook_content);
TextView likeCount = (TextView) view.findViewById(R.id.facebook_likecount);
TextView commentCount = (TextView) view.findViewById(R.id.facebook_commentcount);
TextView createdAt = (TextView) view.findViewById(R.id.facebook_date);
content.setText(item.getTitle());
likeCount.setText(Integer.toString(item.getLikeCount()));
commentCount.setText(Integer.toString(item.getCommentCount()));
createdAt.setText(DateTimeUtils.getInstance(getActivity()).getTimeDiffString(item.getCreatedAt().getTimeInMillis()));
view.setClickable(true);
view.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
((MainActivity) getActivity()).requestNieuwsDetailPage(item);
}
});
return view;
}
}