android - 关于 FragmentTransaction

Question

我在一个 Activity 中有三个 fragment ，并在 Activity 中处理了反压。在一个 fragment 中 back press (CallingFragment) 它加载 DialerFragment因为我在加载 CallingFragement 并提供此日志 时将其添加到后台堆栈。请告诉我为什么会这样？

正在加载调用 fragment :

 void launchCallingFrag(String number, String name ,long time , boolean isongoing,String price )
    {
        String calleename= name;
        if(calleename==null)
        calleename=CommonUtility.getContactDisplayNameByNumber(number, context);

        callingScreenFragment.setNumber( number,calleename ,time,isongoing , price);
        ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.dial_fragment, callingScreenFragment, CALLING_FRAGMENT_TAG);

        dialerFragment = (DialerFragment)getSupportFragmentManager().findFragmentByTag(DIALER_FRAGMENT_TAG);

        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);

            ft.addToBackStack(DIALER_FRAGMENT_TAG);


        ft.commit();
        overridePendingTransition(R.anim.animation1, R.anim.animation2);

    }

背压:

  @Override
public void onBackPressed() {
Log.e("back press called ",""+getSupportFragmentManager().getBackStackEntryCount());
dialerFragment = (DialerFragment)getSupportFragmentManager().findFragmentByTag(DIALER_FRAGMENT_TAG);
if (dialerFragment!=null&&dialerFragment.isVisible()) {
// add your code here
Log.e("dialer fragment","dialer fragment ");
dialerFragment.onBackPress();
}
else {

callingScreenFragment = (CallingScreenFragment) getSupportFragmentManager().findFragmentByTag(CALLING_FRAGMENT_TAG);
if (callingScreenFragment!=null&&callingScreenFragment.isVisible()) {

Log.e("calling  fragment", "calling fragment ");

callingScreenFragment.onBackPress(fromNotification);

}
else {
recentDetailFragment = (RecentDetailFragment) getSupportFragmentManager().findFragmentByTag(LOG_DETAILS_FRAGMENT_TAG);
if (recentDetailFragment!=null&&recentDetailFragment.isVisible()) {
Log.e("recent   fragment","recent fragment ");
recentDetailFragment.onBackPress();
}
else {
super.onBackPressed();
}
}

}

日志:

 02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.addTargets
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.addTransitionTargets
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.beginDelayedTransition
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.captureExitingViews
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve virtual method 12194: Landroid/view/ViewGroup;.isTransitionGroup ()Z
    02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.cleanupTransitions
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.967  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.cloneTransition
    02-05 17:17:04.967  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.977  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.excludeTarget
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve virtual method 12022: Landroid/view/View;.getTransitionName ()Ljava/lang/String;
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve virtual method 12022: Landroid/view/View;.getTransitionName ()Ljava/lang/String;
    02-05 17:17:04.977  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.mergeTransitions
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.977  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.removeTargets
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.977  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.transition.Transition', referenced from method android.support.v4.app.FragmentTransitionCompat21.setEpicenter
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve check-cast 1450 (Landroid/transition/Transition;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to find class referenced in signature (Landroid/transition/Transition;)
            02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ Unable to resolve superclass of Landroid/support/v4/app/FragmentTransitionCompat21$3; (1449)
            02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ Link of class 'Landroid/support/v4/app/FragmentTransitionCompat21$3;' failed
    02-05 17:17:04.977  10280-10280/com.myapp E/dalvikvm﹕ Could not find class 'android.support.v4.app.FragmentTransitionCompat21$3', referenced from method android.support.v4.app.FragmentTransitionCompat21.setSharedElementEpicenter
    02-05 17:17:04.977  10280-10280/com.myapp W/dalvikvm﹕ VFY: unable to resolve new-instance 422 (Landroid/support/v4/app/FragmentTransitionCompat21$3;) in Landroid/support/v4/app/FragmentTransitionCompat21;
    02-05 17:17:04.987  10280-10280/com.myapp W/dalvikvm﹕ Unable to resolve superclass of Landroid/support/v4/app/FragmentTransitionCompat21$1; (1449)
            02-05 17:17:04.987  10280-10280/com.myapp W/dalvikvm﹕ Link of class 'Landroid/support/v4/app/FragmentTransitionCompat21$1;' failed
    02-05 17:17:04.987  10280-10280/com.myapp W/dalvikvm﹕ Unable to resolve superclass of Landroid/support/v4/app/FragmentTransitionCompat21$3; (1449)
            02-05 17:17:04.987  10280-10280/com.myapp W/dalvikvm﹕ Link of class 'Landroid/support/v4/app/FragmentTransitionCompat21$3;' failed

Answer 1

不幸的是，这是由于 android.support.v4 库中的错误尚未解决(截至本回答之日)。

本质上，支持库使用 API 级别 19 和 21 API，即使在没有足够高 API 级别的设备上运行时也是如此。这是一个非常严重(甚至令人震惊)的错误，因为 Android 支持库的全部目的是使应用程序免受 API 级别差异的影响!

在您的情况下，您显然在 API 级别低于 19 的设备上运行，这是整个 android.transition 的时候包被引入。

相关的 Android 问题是:77670和 89244 .您可能想访问这些问题并给它们加注星标，和/或添加一个新问题。