小编hia*_*ngh的帖子

我设计了非常重的嵌套设计，如下所示，当我的列表扩展列表视图时的问题似乎没有滚动这是什么原因，底部表被扩展但没有关注其中的列表视图，如果我滚动触摸“营业时间”文本，它开始滚动，但当它向上时，我无法向下滑动。

_showDialog(BuildContext context) {
    print("_showDialog");
    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      builder: (BuildContext context) {
        return DraggableScrollableSheet(
          expand: false,
          builder: (context, scrollController) {
            return Container(
              child: Stack(
                children: <Widget>[
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: <Widget>[
                      Align(
                          alignment: Alignment.topCenter,
                          child: Container(
                              margin: EdgeInsets.symmetric(vertical: 8),
                              height: 8.0,
                              width: 70.0,
                              decoration: BoxDecoration(
                                  color: Colors.grey[400],
                                  borderRadius: BorderRadius.circular(10.0)))),
                      SizedBox(height: 16),
                      Padding(
                        padding: const EdgeInsets.symmetric(horizontal: 24),
                        child: Text('Operational Hours',
                            style: TextStyle(
                                fontWeight: FontWeight.bold,
                                fontSize: widget.isTab(context)
                                    ? TabTextStyles.mediumText
                                        .copyWith()
                                        .fontSize
                                    : PhoneTextStyles.mediumText
                                        .copyWith()
                                        .fontSize)),
                      ),
                    ],
                  ),
                  ListView(
                    controller: …

片段中有默认构造函数，我想知道它的用途以及它提供的功能？我在没有它的情况下运行代码它工作得很好，我在删除它时找不到任何错误

public class SongListFragment extends Fragment {

   private static final String SONG_IDS = "song_ids";

   // TODO: Rename and change types of parameters
   private int[] songIds;
   private OnFragmentInteractionListener mListener;

   public SongListFragment() {
      // Required empty public constructor
   }

   // TODO: Rename and change types and number of parameters
   public static SongListFragment newInstance(int[] songIds) {
      SongListFragment fragment = new SongListFragment();
      Bundle args = new Bundle();
      args.putIntArray(SONG_IDS, songIds);
      fragment.setArguments(args);
      return fragment;
   }

   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      if (getArguments() != null) …

我的应用无法启动它安装后立即崩溃,我无法理解错误!

我为两个片段创建了两个recylcerView,它们附加在主活动xml文件中

错误:

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.invincible.fragfrag, PID: 14384
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.invincible.fragfrag/com.invincible.fragfrag.MainActivity}: android.view.InflateException: Binary XML file line #14: Error inflating class android.support.v7.app.AlertController.RecycleListView
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2521)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601)
                      at android.app.ActivityThread.access$800(ActivityThread.java:178)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470)
                      at android.os.Handler.dispatchMessage(Handler.java:111)
                      at android.os.Looper.loop(Looper.java:194)
                      at android.app.ActivityThread.main(ActivityThread.java:5637)
                      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:960)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
                   Caused by: android.view.InflateException: Binary XML file line #14: Error inflating class android.support.v7.app.AlertController.RecycleListView
                      at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:757)
                      at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
                      at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:288)
                      at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143)
                      at com.invincible.fragfrag.MainActivity.onCreate(MainActivity.java:13)
                      at android.app.Activity.performCreate(Activity.java:6100) …