我直接从教程here.使用ZoomOutPageTransformer,我有一个导航抽屉,抽屉上的第一项是ViewPager Fragment。这在第一次尝试时效果很好,但是在我转到另一个活动并返回后,它会引发以下错误:
06-29 21:38:06.567 5905-5905/com.hidden.hidden E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.hidden.hidden, PID: 5905
java.lang.IllegalStateException: Recursive entry to executePendingTransactions
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1456)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:482)
at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1073)
at android.support.v4.view.ViewPager.populate(ViewPager.java:919)
at android.support.v4.view.ViewPager.setPageTransformer(ViewPager.java:623)
at com.hidden.hidden.MyFragment.onActivityCreated(MyFragment.java:56)
at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1512)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1121)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1484)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:450)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
我的密码
MyFragment.java中的onActivityCreated()
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mPager = (ViewPager) getView().findViewById(R.id.pager);
mPager.setAdapter(new MyCustomAdapter(getFragmentManager()));
//Line 56
mPager.setPageTransformer(true, new ZoomOutPageTransformer());
mIndicator = (LinePageIndicator) getView().findViewById(R.id.indicator);
mIndicator.setViewPager(mPager);
}
ZoomOutPageTransformer.java
public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
private static final float MIN_SCALE = 0.85f;
private static final float MIN_ALPHA = 0.5f;
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
int pageHeight = view.getHeight();
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 1) { // [-1,1]
// Modify the default slide transition to shrink the page as well
float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
float vertMargin = pageHeight * (1 - scaleFactor) / 2;
float horzMargin = pageWidth * (1 - scaleFactor) / 2;
if (position < 0) {
view.setTranslationX(horzMargin - vertMargin / 2);
} else {
view.setTranslationX(-horzMargin + vertMargin / 2);
}
// Scale the page down (between MIN_SCALE and 1)
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
// Fade the page relative to its size.
view.setAlpha(MIN_ALPHA +
(scaleFactor - MIN_SCALE) /
(1 - MIN_SCALE) * (1 - MIN_ALPHA));
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
同样,转换器直接来自Android开发人员页面。
非常感谢帮助!
最佳答案
使用PageTransformer时遇到相同的问题。就我而言,解决方案是在将适配器设置为我的viewPager之前调用pager.setPageTransformer()。
cardsPager.setPageTransformer(true, new CardsPageTransformer());
cardsPager.setAdapter(new CardsPagerAdapter(getFragmentManager()));