我有一个片段,它向选项菜单添加一个选项。当单击此选项时,会打开一个对话框片段。对话框将原始片段设置为其目标片段。如果在对话框片段打开时没有发生方向更改,则目标片段符合预期。但是,在方向更改后,目标片段被设置为对话框片段本身,而不是之前设置的片段。因此,当尝试将目标片段强制转换为设定的片段时,我会得到一个ClassCastException。我需要在我的对话框中获取目标片段,因为它实现了回调(OnStartOrRestartLoader)。
在实现OnStartOrRestartLoader的片段(VirsārstsFragment)中,我按以下方式创建对话框:
在实现OnStartOrRestartLoader的片段(VirsārstsFragment)中,我按以下方式创建对话框:
FragmentManager fm = getChildFragmentManager();
SearchDialogFragment dialog = new SearchDialogFragment();
dialog.show(fm, "searchDialog");
dialog.setTargetFragment(this, DIALOGFRAGMENT);
然后在SearchDialogFragment中,我执行以下操作来设置回调:
OnStartOrRestartLoader callback = (OnStartOrRestartLoader) getTargetFragment();
日志记录:
08-25 12:15:55.087: E/AndroidRuntime(10057): FATAL EXCEPTION: main
08-25 12:15:55.087: E/AndroidRuntime(10057): Process: com.example, PID: 10057
08-25 12:15:55.087: E/AndroidRuntime(10057): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.MainActivity}: java.lang.ClassCastException: com.example.SearchDialogFragment cannot be cast to com.example.OnStartOrRestartLoader
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2224)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2273)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3759)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.access$900(ActivityThread.java:141)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.os.Handler.dispatchMessage(Handler.java:102)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.os.Looper.loop(Looper.java:136)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.main(ActivityThread.java:5052)
08-25 12:15:55.087: E/AndroidRuntime(10057): at java.lang.reflect.Method.invokeNative(Native Method)
08-25 12:15:55.087: E/AndroidRuntime(10057): at java.lang.reflect.Method.invoke(Method.java:515)
08-25 12:15:55.087: E/AndroidRuntime(10057): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
08-25 12:15:55.087: E/AndroidRuntime(10057): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
08-25 12:15:55.087: E/AndroidRuntime(10057): at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:132)
08-25 12:15:55.087: E/AndroidRuntime(10057): at dalvik.system.NativeStart.main(Native Method)
08-25 12:15:55.087: E/AndroidRuntime(10057): Caused by: java.lang.ClassCastException: com.example.SearchDialogFragment cannot be cast to com.example.OnStartOrRestartLoader
08-25 12:15:55.087: E/AndroidRuntime(10057): at com.example.SearchDialogFragment.onCreateDialog(SearchDialogFragment.java:59)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.DialogFragment.getLayoutInflater(DialogFragment.java:307)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1121)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1103)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1901)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1518)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:962)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1121)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1103)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1901)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:567)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.Activity.performStart(Activity.java:5322)
08-25 12:15:55.087: E/AndroidRuntime(10057): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2187)
08-25 12:15:55.087: E/AndroidRuntime(10057): ... 13 more
getTargetFragment()
返回一个Fragment
,而你正在尝试将其转换为OnStartOrRestartLoader
。异常非常清楚。你想做什么? - Simon