在我的MainActivity中，我使用FragmentPagerAdapter的实例来创建两个片段。但我总是得到类似的东西：
java.lang.IllegalStateException: Recursive entry to executePendingTransactions
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1544)
at android.support.v4.app.FragmentManagerImpl.saveAllState(FragmentManager.java:1756)
at android.support.v4.app.FragmentController.saveAllState(FragmentController.java:125)
at android.support.v4.app.FragmentActivity.onSaveInstanceState(FragmentActivity.java:487)
at android.app.Activity.performSaveInstanceState(Activity.java:1182)
at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1230)
at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3019)
at android.app.ActivityThread.handleStopActivity(ActivityThread.java:3078)
at android.app.ActivityThread.access$1000(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1263)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4960)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
at dalvik.system.NativeStart.main(Native Method)
这是我的代码：
public class MainActivity extends AppCompatActivity
implements ManagerCallback,ViewPager.PageTransformer{
private MediaManager mediaManagers[]=new MediaManager[2];
private ViewPager mainPager;
private ArrayList<String> mediaData;
private static final float MIN_SCALE = 0.85f;
private static final float MIN_ALPHA = 0.5f;
private static final int IMAGE_RECREATE_REQUEST=1;
private static final int AUDIO_RECREATE_REQUEST=2;
private FragmentRefreshListener[] fragmentRefreshListeners;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainPager=(ViewPager)findViewById(R.id.main_pager);
updateAdapter();
setFabButton();
mainPager.setPageTransformer(false, this);
}
private void updateAdapter(){
PagerAdapter pagerAdapter=new MyFragmentPagerAdapter(getSupportFragmentManager());
mainPager.setAdapter(pagerAdapter);
fragmentRefreshListeners=new FragmentRefreshListener[2];
}
private void setFabButton(){
setSupportActionBar((Toolbar) findViewById(R.id.main_toolbar));
final FloatingActionButton floatingActionButton=(FloatingActionButton)
findViewById(R.id.floating_main);
floatingActionButton.setImageDrawable(getResources().getDrawable(R.drawable.floating_but));
float alpha=floatingActionButton.getAlpha();
floatingActionButton.animate().alpha(0);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int position = mainPager.getCurrentItem();
switch (position % 2) {
case 0: {
if (mediaManagers[mainPager.getCurrentItem()] != null) {
mediaData = ((ImageManager) mediaManagers[0]).getMediaFiles();
Intent intent = new Intent(MainActivity.this, ImageSelecter.class);
Toast.makeText(getApplicationContext(), "Click", Toast.LENGTH_SHORT).show();
intent.putExtra("pos", -1);
intent.putStringArrayListExtra("images", mediaData);
startActivityForResult(intent,IMAGE_RECREATE_REQUEST);
break;
}
}
case 1: {
if (mediaManagers[mainPager.getCurrentItem()] != null) {
mediaData = ((AudioManager) mediaManagers[1]).getMediaFiles();
Toast.makeText(getApplicationContext(),Integer.toString(mediaData.size()),Toast.LENGTH_SHORT).show();
Intent intent = new Intent(MainActivity.this, AudioList.class);
intent.putStringArrayListExtra("audioNames", mediaData);
intent.putExtra("position", mediaManagers[mainPager
.getCurrentItem()].directoriesNumber());
startActivityForResult(intent,AUDIO_RECREATE_REQUEST);
}
break;
}
}
}
});
floatingActionButton.animate().alpha(alpha);
}
@Override
public void onActivityResult(int requestCode, int resultCode,Intent data){
if(requestCode==IMAGE_RECREATE_REQUEST){
if(resultCode==RESULT_OK)
fragmentRefreshListeners[0].onRefresh();
}
else if(requestCode==AUDIO_RECREATE_REQUEST){
if(resultCode==RESULT_OK)
fragmentRefreshListeners[1].onRefresh();
}
}
public void transformPage(View view, float position) {
int pageWidth = view.getWidth();
int pageHeight = view.getHeight();
if (position < -1) {
view.setAlpha(0);
} else if (position <= 1) {
float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
float verticalMargin = pageHeight* (1 - scaleFactor) / 2;
float horizontalMargin = pageWidth * (1 - scaleFactor) / 2;
if (position < 0) {
view.setTranslationX(horizontalMargin - verticalMargin / 2);
} else {
view.setTranslationX(-horizontalMargin + verticalMargin / 2);
}
view.setScaleX(scaleFactor);
view.setScaleY(scaleFactor);
view.setAlpha(MIN_ALPHA +
(scaleFactor - MIN_SCALE) /
(1 - MIN_SCALE));
} else {
view.setAlpha(0);
}
}
private class MyFragmentPagerAdapter extends FragmentPagerAdapter{
public MyFragmentPagerAdapter(android.support.v4.app.FragmentManager fm) {
super(fm);
}
@Override
public android.support.v4.app.Fragment getItem(int position) {
switch (position)
{
case 0:
{
ImageFragment imageFragment=ImageFragment.getInstance(MainActivity.this);
fragmentRefreshListeners[0]=imageFragment;
return imageFragment;
}
case 1:
{
AudioFragment audioFragment=AudioFragment.getInstance(MainActivity.this);
fragmentRefreshListeners[1]=audioFragment;
return audioFragment;
}
}
Toast.makeText(MainActivity.this,"Error",Toast.LENGTH_SHORT).show();
return null;
}
@Override
public int getCount() {
return 2;
}
public void destroyItem(ViewGroup container, int position, Object object){
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public void setManager(MediaManager manager, int viewPosition){
mediaManagers[viewPosition]=manager;
}
}