我只能使用ViewPager向後翻頁並且不能翻頁。我只能使用ViewPager向後翻頁並且不能向前翻頁
我writint的旗幟,但我只能用ViewPager向後頁面,不能向前翻頁。
這是我寫的適配器。
class MyPagerAdapter extends PagerAdapter {
@Override
public Object instantiateItem(ViewGroup container, int position) {
int p = position % mImgRes.length;
container.addView(mListView.get(p));
return mListView.get(p);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
@Override
public int getCount() {
return 100;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return (view == object);
}
}
這是一條錯誤消息。當我向前滾動
07-29 20:45:02.098 20791-20791/com.example.myfirstpro E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.myfirstpro, PID: 20791 java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first. at android.view.ViewGroup.addViewInner(ViewGroup.java:4465) at android.view.ViewGroup.addView(ViewGroup.java:4301) at android.support.v4.view.ViewPager.addView(ViewPager.java:1505) at android.view.ViewGroup.addView(ViewGroup.java:4242) at android.view.ViewGroup.addView(ViewGroup.java:4215) at com.example.myfirstpro.MainFragment$MyPagerAdapter.instantiateItem(MainFragment.java:62) at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:1034) at android.support.v4.view.ViewPager.populate(ViewPager.java:1216) at android.support.v4.view.ViewPager.populate(ViewPager.java:1116) at android.support.v4.view.ViewPager$3.run(ViewPager.java:273) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:892) at android.view.Choreographer.doCallbacks(Choreographer.java:704) at android.view.Choreographer.doFrame(Choreographer.java:637) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:878) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5628) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:853) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:737)
程序將會崩潰。
這是除了比適配器以外。@閎督安
private ViewPager mVpScroll;
private int mImgRes[] = new int[] {
R.drawable.banner01,
R.drawable.banner02,
R.drawable.banner03
};
private List<View> mListView = new ArrayList<>();
private LayoutInflater mInfalte;
public MainFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
for (int i = 0; i < mImgRes.length; i++) {
View inflate = inflater.inflate(R.layout.fragment_main_scroll_item, null);
ImageView ivBanner = (ImageView) inflate.findViewById(R.id.iv_scroll);
ivBanner.setImageResource(mImgRes[i]);
mListView.add(inflate);
}
mInfalte = inflater;
return inflater.inflate(R.layout.fragment_main, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
mVpScroll = (ViewPager) view.findViewById(R.id.vp_scroll);
mVpScroll.setAdapter(new MyPagerAdapter());
}
你想使唯一正確的走一個方向? –
使用'FragmentStatePagerAdapter',而不是'PagerAdapter' – matoni
見我這個答案將幫助您:https://stackoverflow.com/a/45389635/5743202 –