android - 片段的onCreate和onCreateView不会被调用

android - 片段的onCreate和onCreateView不会被调用,第1张

我正在构建一个接收动作的应用程序。发送ListView并将剪辑数据中的所有文件显示为ListView。我的ShareFragment位于由MainActiviy托管的public class ShareFragment extends MFragment { private static final String TAG = "ShareFragment"; private List<File> files; private FileAdapter fileAdapter; @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); Log.e(TAG, "onCreate called"); } @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { files = new ArrayList<>(); fileAdapter = new FileAdapter(getActivity(), 0, files); View rootView = inflater.inflate(R.layout.share_fragment, container, false); ListView lv = (ListView) rootView.findViewById(R.id.listView); lv.setAdapter(fileAdapter); Log.e(TAG, "onCreateView called"); return rootView; } public void setData(List<File> files){ Log.e(TAG, "setData called"); this.files = files; fileAdapter.notifyDataSetChanged(); } 内。以下是我如何实现它。

MainActivity

以下是我在@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Intent intent = getIntent(); shareFragment = (ShareFragment) getSupportFragmentManager().findFragmentByTag("share_fragment"); if(shareFragment == null) { shareFragment = new ShareFragment(); shareFragment.setTitle("Share"); } FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); ft.add(R.id.fl_root, shareFragment, "share_fragment"); ft.commit(); handleIntent(intent); }

中使用它的方式
handleIntent

以下是private void handleIntent(Intent intent) { String action = intent.getAction(); String type = intent.getType(); if ((Intent.ACTION_SEND.equals(action) || Intent.ACTION_SEND_MULTIPLE.equals(action)) && type != null) { int size = intent.getClipData().getItemCount(); List<File> files = new ArrayList<>(); for (int i = 0; i < size; i ) { File file = new File(intent.getClipData().getItemAt(i).getUri().getPath()); files.add(file); } shareFragment.setData(files); } } 方法:

action.SEND

我的问题是 当我的应用程序通过收到Intent onCreate启动时,它会遇到shareFragment = new ShareFragment()并处理此行​​onCreate

但是 永远不会调用onCreateView的{​​{1}}和ShareFragment。的为什么吗

注意我认为FragmentManager在我的应用首次运行时保留了ShareFragment的实例。所以我试图找到我的片段重用它,但它总是返回null。

修改 我在NullPointerException

处找到了fileAdapter.notifyDataSetChanged();
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void icetea.com.quickshare.adapter.FileAdapter.notifyDataSetChanged()' on a null object reference
            at icetea.com.quickshare.fragments.ShareFragment.setData(ShareFragment.java:49)
            at icetea.com.quickshare.MainActivity.handleIntent(MainActivity.java:63)
            at icetea.com.quickshare.MainActivity.onCreate(MainActivity.java:46)
            at android.app.Activity.performCreate(Activity.java:6374)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2767)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2879)
            at android.app.ActivityThread.access0(ActivityThread.java:182)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1475)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:145)
            at android.app.ActivityThread.main(ActivityThread.java:6141)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)

最佳答案:

1 个答案:

答案 0 :(得分:1)

template_vars = headers[1:] kwargs = dict.fromkeys(template_vars) 移至 onResume()

您尝试在onCreate中设置数据,但此时片段尚未创建

您可以在Fragments文档中找到更多相关信息: http://developer.android.com/guide/components/fragments.html#Lifecycle

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