AndroidX 迁移后，ListView 未在 OnCreate/OnStart 上显示任何数据

如何解决AndroidX 迁移后，ListView 未在 OnCreate/OnStart 上显示任何数据

我有一个应用程序，它只显示数据，直到我在 SearchView 上过滤某些内容。现在，在以下示例中，我将在 Home Activity 和 More Sites Activity （发生错误的地方） 之间切换。

正如您在我切换到“更多站点”活动时所看到的，它唯一的 ListView 一直保持为空，直到我“过滤”了某些内容。重要的是要强调，在我将应用迁移到 AndroidX 之前，More Sites Activity 过去可以正常工作。

这是我当前代码的一部分：

other_ruins.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">
           <include layout="@layout/search_container" />
            <ListView
                android:id="@+id/lstOtherRuins"
                android:layout_margin="8dp"
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:choiceMode="singleChoice"
                android:layout_gravity="left|start" />
        </LinearLayout>
    </androidx.coordinatorlayout.widget.CoordinatorLayout>
    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:adSize="SMART_BANNER"
        app:adUnitId="@string/banner_ad_unit_id" />
</LinearLayout>

search_container.xml

<?xml version="1.0" encoding="UTF-8" ?>
<FrameLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        app:theme="@style/ToolBarStyle"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@color/colorPrimary" />

    <com.miguelcatalan.materialsearchview.MaterialSearchView
        android:id="@+id/search_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</FrameLayout>

这是我的 C# 代码，在这两种情况下，我都使用 UpdateListView 方法：

protected override void OnStart()
{
    base.OnStart();

    UpdateListView(AllRuins);
}

private void UpdateListView(List<Row> result)
{
    List<IMenuItemsType> item = new();

    string prevCountry = "";

    foreach (var datum in result)
    {
        if (datum.Col3 != prevCountry)
        {
            prevCountry = datum.Col3;
            item.Add(new MenuHeaderItem(prevCountry));
        }

        item.Add(new MenuContentSimpleItem(datum.Col1,datum.Col2,datum.Col3,datum.Col4,datum.Col5));
    }

    LstOtherRuins.Adapter = new OtherRuinsAdapter(this,item);
}

这是 SearchView 过滤器：

public partial class OtherRuinsActivity
{
    public class MaterialSearchViewListener : java.lang.Object,MaterialSearchView.IOnQueryTextListener
    {
        private readonly OtherRuinsActivity OActivity;

        public MaterialSearchViewListener(OtherRuinsActivity oActivity)
        {
            OActivity = oActivity;
        }

        public bool OnQueryTextChange(string p0)
        {
            OActivity.CurrentWord = p0;
            OActivity.UpdateListView(OActivity.AllRuins.Where(x => x.Col1.ToLower().Contains(p0)).ToList());

            return true;
        }

        public bool OnQueryTextSubmit(string p0)
        {
            OActivity.CurrentWord = p0;
            OActivity.UpdateListView(OActivity.AllRuins.Where(x => x.Col1.ToLower().Contains(p0)).ToList());

            return true;
        }
    }
}

我已经验证并有数据：

这也是我的适配器：

public partial class OtherRuinsAdapter
{
    private class OtherRuinsViewHolder : java.lang.Object
    {
        public TextView LblName { get; set; }
        public TextView LblLocation { get; set; }
    }
}

public partial class OtherRuinsAdapter : ArrayAdapter<IMenuItemsType>
{
    public OtherRuinsAdapter(Context context,List<IMenuItemsType> items) : base(context,items)
    {
        Context1 = context;
        Items = items;
        Inflater = (LayoutInflater)Context1.GetSystemService(Context.LayoutInflaterService);
    }

    public override int Count
    {
        get
        {
            return Items.Count;
        }
    }

    public Context Context1 { get; set; }
    public List<IMenuItemsType> Items { get; set; }
    public LayoutInflater Inflater { get; set; }
    public LayoutInflater Inflater1 { get => Inflater; set => Inflater = value; }

    public override long GetItemId(int position)
    {
        return position;
    }

    public override View GetView(int position,View convertView,ViewGroup parent)
    {
        var inflater = LayoutInflater.From(parent.Context);
        OtherRuinsViewHolder holder = null;
        var view = convertView;

        if (view != null)
        {
            holder = view.Tag as OtherRuinsViewHolder;
        }

        if (holder == null)
        {
            holder = new OtherRuinsViewHolder();
            view = inflater.Inflate(Resource.Layout.other_ruins_list,parent,false);
            holder.LblName = view.FindViewById<TextView>(Resource.Id.lblName);
            holder.LblLocation = view.FindViewById<TextView>(Resource.Id.lblLocation);
            view.Tag = holder;
        }

        IMenuItemsType item = Items[position];
        if (item.GetMenuItemsType() == 0)
        {
            MenuHeaderItem _headerItem = (MenuHeaderItem)item;
            view = inflater.Inflate(Resource.Layout.listview_header_item,null);
            // user dont click header item
            view.Clickable = false;

            var headerName = view.FindViewById<TextView>(Resource.Id.txtHeader);
            headerName.Text = _headerItem.HeaderText;

        }
        else if (item.GetMenuItemsType() == 1)
        {
            MenuContentSimpleItem _contentItem = (MenuContentSimpleItem)item;

            if (!string.IsNullOrEmpty(_contentItem.Wiki))
            {
                holder.LblName.PaintFlags = PaintFlags.UnderlineText;
                holder.LblName.SetTextColor(Color.Argb(255,10,150,124));
                holder.LblName.Click += LblName_Click;
            }
            else
            {
                holder.LblName.PaintFlags = PaintFlags.AntiAlias;
                holder.LblName.SetTextColor(Color.Argb(255,33,33));
                holder.LblName.Click -= LblName_Click;
            }

            if (!string.IsNullOrEmpty(_contentItem.SubScript))
            {
                if (Build.VERSION.SdkInt >= BuildVersionCodes.N)
                    holder.LblName.SetText(Html.FromHtml($"{_contentItem.Title}<sub><small>{_contentItem.SubScript}</small></sub>",FromHtmlOptions.ModeLegacy),BufferType.Spannable);
                else
#pragma warning disable CS0618 // Type or member is obsolete
                    holder.LblName.SetText(Html.FromHtml($"{_contentItem.Title}<sub><small>{_contentItem.SubScript}</small></sub>"),BufferType.Spannable);
#pragma warning restore CS0618 // Type or member is obsolete
            }
            else
            {
                holder.LblName.Text = _contentItem.Title;
            }

            holder.LblLocation.Text = _contentItem.Description;
            holder.LblLocation.PaintFlags = PaintFlags.UnderlineText;
            holder.LblLocation.Click += LblLocation_Click;
        }

        return view;
    }

    private void LblName_Click(object sender,System.EventArgs e)
    {
        Context1.StartActivity(new Intent(Intent.ActionView,Android.Net.Uri.Parse(new XML2CSharp("OtherRuins.xml").FromXml<Book>().Row.Where(x => x.Col1 == ((TextView)sender).Text).FirstOrDefault().Col4)));
    }

    private void LblLocation_Click(object sender,System.EventArgs e)
    {
        Intent mapIntent = new Intent(Intent.ActionView,Android.Net.Uri.Parse($"google.navigation:q={((TextView)sender).Text},{new XML2CSharp("OtherRuins.xml").FromXml<Book>().Row.Where(x => x.Col2 == ((TextView)sender).Text).FirstOrDefault().Col3}"));
        mapIntent.SetPackage("com.google.android.apps.maps");
        Context1.StartActivity(mapIntent);
    }
}

附注：

由于此布局，似乎没有调用 GetView：

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
   <include layout="@layout/search_container" />
    <ListView
        android:id="@+id/lstOtherRuins"
        android:layout_margin="8dp"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:choiceMode="singleChoice"
        android:layout_gravity="left|start" />
</LinearLayout>

如果我删除 LinearLayout，那么它可以工作，但会生成一个新错误：

A ListView overlaps a SearchView in a CoordinatorLayout

解决方法

不知何故，GetView 方法没有被调用，因为 LinerLayout 包含 ListView。我重新编写了布局，现在它可以正常工作了。

other_ruins.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <include layout="@layout/search_container" />
        <ListView
            android:id="@+id/lstOtherRuins"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            android:nestedScrollingEnabled="true"
            android:layout_margin="8dp"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:choiceMode="singleChoice"
            android:layout_below="@id/toolbar_container"
            android:layout_gravity="left|start" />
    </androidx.coordinatorlayout.widget.CoordinatorLayout>
    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:adSize="SMART_BANNER"
        app:adUnitId="@string/banner_ad_unit_id" />
</LinearLayout>

此外，我需要通过添加 AppBarLayout 来更改容器，因为它是重叠的。

search_container.xml：

<?xml version="1.0" encoding="UTF-8" ?>
<com.google.android.material.appbar.AppBarLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar_container"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            app:theme="@style/ToolBarStyle"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@color/colorPrimary" />

        <com.miguelcatalan.materialsearchview.MaterialSearchView
            android:id="@+id/search_view"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </FrameLayout>

</com.google.android.material.appbar.AppBarLayout>