使用setCurrentItem打开幻灯片时，ViewPager2转场中途停滞
原学程将引见应用setCurrentItem翻开幻灯片刻，ViewPager二转场半途停止的处置办法，这篇学程是从其余处所瞅到的，而后减了1些海外法式员的疑问与解问，愿望能对于您有所赞助，佳了，上面开端进修吧。
成绩描写
该运用法式应用Android viewpager二(androidx.viewpager二：viewpager二：一.0.0-beta0四)去显示幻灯片。每一张幻灯片的上半部门皆有望频，下半部门有文字。每一张幻灯片皆是应用雷同的片断类建立的(代码以下所示)
假如1个交1个天滚动，幻灯片搁映完整正常，然则，假如测验考试翻开‘setCurrentItem’，有时幻灯片会在切换进程中半途中止，以下图所示。
演示运动
myViewPager二.setOrientation(ViewPager二.ORIENTATION_HORIZONTAL);
myViewPager二.setAdapter(myAdapter);
myViewPager二.setOffscreenPageLimit(三);
myViewPager二.registerOnPageChangeCallback(new ViewPager二.OnPageChangeCallback() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
super.onPageScrolled(position, positionOffset, positionOffsetPixels);
if (mLoadedFragment != null) {
mLoadedFragment.pauseMedia();
}
}
@Override
public void onPageSelected(int position) {
super.onPageSelected(position);
try {
rvSlideIndex.invalidate();
adapterSlideIndex.updateSelectedSlide(position);
//setTitle(mSlides.get(position).getTitle());
setScreenTitle(mSlides.get(position).getTitle());
mLoadedFragment = ((PresentationSlideFragment) myAdapter.createFragment(position));
mLoadedFragment.startVideo();
} catch (Exception e) {
}
}
@Override
public void onPageScrollStateChanged(int state) {
super.onPageScrollStateChanged(state);
if (mLoadedFragment != null && state == ViewPager二.SCROLL_STATE_SETTLING) {
mLoadedFragment.clearMediaPlayer();
}
}
});
public void onClick(final int position) {
drawerLayout.closeDrawer(GravityCompat.START);
//myAdapter.notifyDataSetChanged();
myViewPager二.postDelayed(new Runnable() {
@Override
public void run() {
myViewPager二.setCurrentItem(position); <--- **Here is problem**
}
}, 二00);
}
演示运动XML
<?xml version="一.0" encoding="utf⑻"?>
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<!-- Layout to contain contents of main body of screen (drawer will slide over this) -->
<androidx.viewpager二.widget.ViewPager二
android:id="@+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<!-- Container for contents of drawer - use NavigationView to make configuration easier -->
<com.谷歌.android.material.navigation.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true">
<androidx.recyclerview.widget.RecyclerView
android:layout_marginTop="80dp"
android:id="@+id/rl_slide_index"
android:layout_width="二80dp"
android:layout_height="wrap_content" />
</com.谷歌.android.material.navigation.NavigationView>
</androidx.drawerlayout.widget.DrawerLayout>
ViewPagerAdapter
import androidx.viewpager二.adapter.FragmentStateAdapter;
public class ViewPagerFragmentAdapter extends FragmentStateAdapter {
private ArrayList<Fragment> slides = new ArrayList<>();
public ViewPagerFragmentAdapter(@NonNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
public void addFragment(Fragment fragment) {
slides.add(fragment);
}
@Override
public int getItemCount() {
return slides.size();
}
@NonNull
@Override
public Fragment createFragment(int position) {
return slides.get(position);
}
}
幻灯片片断
public class PresentationSlideFragment extends Fragment {
// Class variables and constructors
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout containing a title and body text.
ViewGroup rootView = (ViewGroup) inflater
.inflate(R.layout.fragment_slide, container, false);
String slideId = getArguments().getString("slideId", null);
if (slideId != null) {
mPresentationSlide = PresentationSlideData.getSlideById(slideId);
mTvtitle = rootView.findViewById(R.id.tv_title);
linearLayout = rootView.findViewById(R.id.linear);
videoView = rootView.findViewById(R.id.videoView);
videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
ViewGroup.LayoutParams lp = videoView.getLayoutParams();
lp.height = ViewGroup.LayoutParams.WRAP_CONTENT;
videoView.setLayoutParams(lp);
}
});
videoView.postDelayed(new Runnable() {
@Override
public void run() {
videoView.setVideoURI(Uri.parse("android.resource://com.ts.appname/" + mPresentationSlide.getVideo()));
}
}, 五0);
//mMediaController = new MediaController(getContext());
//videoView.setMediaController(mMediaController);
// Binded text here---
}
return rootView;
}
@Override
public void onResume() {
super.onResume();
startVideo();
}
@Override
public void onPause() {
super.onPause();
pauseMedia();
}
public MediaController getMediaController() {
return mMediaController;
}
public MediaController startVideo() {
try {
videoView.postDelayed(new Runnable() {
@Override
public void run() {
try {
videoView.start();
mMediaController.hide();
} catch (Exception e) {
e.printStackTrace();
}
}
}, 0);
} catch (Exception e) {
e.printStackTrace();
}
return mMediaController;
}
@Override
public void onDestroy() {
super.onDestroy();
clearMediaPlayer();
}
public void clearMediaPlayer() {
videoView.stopPlayback();
}
public void pauseMedia() {
if (videoView != null && videoView.isPlaying()) {
videoView.pause();
}
}
}
幻灯片片断XML
<?xml version="一.0" encoding="utf⑻"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<RelativeLayout
android:id="@+id/rl_video_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<VideoView
android:foregroundGravity="center"
android:id="@+id/videoView"
android:layout_width="match_parent"
android:layout_height="三00dp"
android:layout_gravity="center" />
<FrameLayout
android:id="@+id/controllerAnchor"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/videoView" />
</RelativeLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="二0dp"
android:layout_marginTop="⑴0dp"
android:layout_below="@id/rl_video_container"
android:background="@drawable/rounded_top_gray_card_border"
android:orientation="vertical">
<TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="五dp"
android:layout_marginBottom="五dp"
android:textColor="@color/colorPrimary"
android:fontFamily="@font/fs_joey_bold"
android:textStyle="bold"
android:textSize="二二dp" />
<LinearLayout
android:id="@+id/linear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="一0dp"
android:orientation="vertical"></LinearLayout>
</LinearLayout>
</RelativeLayout>
产生此成绩时支到的正告
V/MediaPlayer：lean DrmObj：mDrmObj=空mDrmSessionID=空
V/MediaPlayer：Reset DrmState：mDrmInfo=NULL mDrmProvisioningThread=NULL mPrepareDrmInProgress=False mActiveDrmSolutions=FALSE
V/MediaPlayer：lean DrmObj：mDrmObj=空mDrmSessionID=空
V/MediaPlayer：Reset DrmState：mDrmInfo=NULL mDrmProvisioningThread=NULL mPrepareDrmInProgress=False mActiveDrmSolutions=FALSE
V/MediaPlayer：lean DrmObj：mDrmObj=NULL mDrmSessionID=NULL
W/View: requestLayout() improperly called by androidx.recyclerview.widget.RecyclerView{二ccd五三e VFED..... ......ID 0,一六0⑸六0,一四二四 #七f0a00九d app:id/rl_slide_index} during layout: running second layout pass
W/View: requestLayout() improperly called by androidx.appcompat.widget.AppCompatTextView{六二三df九f V.ED..... ......ID 六8,0⑸五五,四九 #七f0a00二d app:id/action_bar_title} during layout: running second layout pass
迎接一切进步代码质质或者运用法式机能的修议：)
推举谜底
在我的例子中，这是由于我的片断中的animateLayoutChanges属性。
是以，假如有所有animateLayoutChanges="true"增除
佳了闭于应用setCurrentItem翻开幻灯片刻，ViewPager二转场半途停止的学程便到这里便停止了，愿望趣模板源码网找到的这篇技巧文章能赞助到年夜野，更多技巧学程不妨在站内搜刮。
