Question

我想使用相同的片段并用重置函数替换内容但是当为每个标签返回相同的片段时，我得到以下错误：

无法更改片段FragmentRank的标签

这是我的代码：

class pagerAdapter extends FragmentPagerAdapter {

String[] tabs = {"1", "2", "3"};
FragmentRank rank;

public pagerAdapter(FragmentManager fm) {
    super(fm);
    rank = FragmentRank.newInstance();
}

@Override
public CharSequence getPageTitle(int position) {
    return tabs[position];
}

@Override
public int getCount() {
    return 3;
}

@Override
public Fragment getItem(int position) {

    return rank;


}


}

有什么想法吗？

logcat：

java.lang.IllegalStateException: Can't change tag of fragment FragmentRank{529c3b00 id=0x7f080044 android:switcher:2131230788:0}: was android:switcher:2131230788:0 now android:switcher:2131230788:1
                    at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:398)
                    at android.support.v4.app.BackStackRecord.add(BackStackRecord.java:389)
                    at android.support.v4.app.FragmentPagerAdapter.instantiateItem(FragmentPagerAdapter.java:99)
                    at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:832)
                    at android.support.v4.view.ViewPager.populate(ViewPager.java:1048)
                    at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
                    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
                    at android.view.View.measure(View.java:16497)
                    at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
                    at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
                    at android.view.View.measure(View.java:16497)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                    at android.view.View.measure(View.java:16497)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
                    at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
                    at android.view.View.measure(View.java:16497)
                    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
                    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
                    at android.view.View.measure(View.java:16497)
                    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1912)
                    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1109)
                    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1291)
                    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:996)
                    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5600)
                    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
                    at android.view.Choreographer.doCallbacks(Choreographer.java:574)
                    at android.view.Choreographer.doFrame(Choreographer.java:544)
                    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
                    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)

Answer 1

FragmentPager中的每个页面都需要有一个不同的Fragment，否则它无法在配置更改时重新创建它。它使用内部命名约定来标识每个片段并重新创建它。因此，每次调用getItem（）时都会返回FragmentRank.newInstance（）。

如果您想要更好地控制适配器内的Fragments，请使用以下方法：https://stackoverflow.com/a/15261142/535762

通过此，您可以重新附加您可能拥有的任何州信息。最好在你的片段的onResume（）里面做这个

在适配器中返回相同的片段

1 个答案: