我有一个活动,我正在设置 viewPager 适配器,如下所示
public class ViewPagerAdapter extends FragmentPagerAdapter {
private int pagerLength;
private HashMap<Integer, String> mFragmentTags;
private FragmentManager mFragmentManager;
String page = "Page";
public ViewPagerAdapter(FragmentManager fm, int numPage) {
super(fm);
mFragmentManager = fm;
pagerLength = numPage;
mFragmentTags = new HashMap<Integer, String>();
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
Object obj = super.instantiateItem(container, position);
if(obj instanceof Fragment) {
Fragment f = (Fragment) obj;
String tag = f.getTag();
mFragmentTags.put(position, tag);
}
return obj;
}
@Override
public Fragment getItem(int index) {
ImageFragment imageFragment = (ImageFragment)Fragment.instantiate(ImageActivity.this, imageFragment.class.getName(), null);
return imageFragment;
}
@Override
public int getCount() {
return pagerLength;
}
public Fragment getFragment(int position) {
String tag = mFragmentTags.get(position);
if (tag == null) {
return (Fragment)instantiateItem(mViewPager, position);
}
Fragment fragment = mFragmentManager.findFragmentByTag(tag);
return fragment;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
mFragmentTags.remove(position);
super.destroyItem(container, position, object);
}
@Override
public CharSequence getPageTitle(int position) {
// TODO Auto-generated method stub
return "TESTING"; //Remove later
}
}
ImageFragment 什么都不是,它只是一个在其布局中带有 imageView 的片段
现在我想在活动片段的 imageView 中设置一个图像,我应该怎么做?
我尝试在我的活动中进行 fn 更新并将 imageUrl 传递给片段中称为更新的函数。问题是虽然片段中的 update() 被调用并接收到图像的 url,但片段的 onCreateView() 从未被调用