【发布时间】：2017-04-26 13:37:40
【问题描述】：
我尝试在 SlideMenu 中使用 RecyclerView。
我将这个示例用于我的 SlideMenu：https://github.com/jamesmontemagno/PagerSlidingTabStrip-for-Xamarin.Android
现在，我添加了带有 SlideMenu 的 RecyclerView。我需要两个菜单：“菜单”和“产品”，所以我为我的片段使用两个 xml 文件：menu.xml 用于“菜单”，menu_recyclerView.xml 用于“产品”。
这是我的代码：
Main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:fitsSystemWindows="true" >
<include
android:id="@+id/top_menu"
layout="@layout/top_menu"/>
<com.refractored.PagerSlidingTabStrip
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:pstsShouldExpand="true"
android:background="@color/Blue"
app:pstsDividerWidth="1dp"
app:pstsDividerPadding="12dp"
app:pstsDividerColor="#50FFFFFF"
android:textColor="@color/Green"
app:pstsTextColorSelected="@color/White"
app:pstsIndicatorColor="@color/Red"
app:pstsUnderlineColor="@color/White"/>
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
menu_recyclerView.xml
<?xml version="1.0" encoding="utf-8" ?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
android:id="@+id/menu_recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v7.widget.CardView>
</LinearLayout>
row_recyclerView 是我的项目的模式
row_recyclerView.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:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="1dp">
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:paddingRight="15dp"
android:paddingLeft="15dp"
android:orientation="vertical">
<refractored.controls.CircleImageView
android:id="@+id/imageView"
app:civ_border_width="2dp"
app:civ_border_color="#000000"/>
</LinearLayout>
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="88"
android:orientation="vertical"
android:paddingRight="10dp"
android:paddingLeft="10dp"
android:paddingTop="7dp"
android:paddingBottom="7dp">
<TextView
android:text="Name"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtName"
android:textColor="#000"
android:gravity="center_vertical"
android:padding="2dp"
android:textSize="18sp" />
<TextView
android:text="Brand"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtBrand"
android:textColor="#000"
android:gravity="center_vertical"
android:padding="2dp"
android:textSize="14sp"
android:singleLine="true" />
<TextView
android:text="Description"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/txtDescription"
android:textColor="#000"
android:gravity="center_vertical"
android:padding="2dp"
android:textSize="16sp" />
</LinearLayout>
</LinearLayout>
-
public class MainActivity : BaseActivity
{
protected override int LayoutResource
{
get
{
return Resource.Layout.Main;
}
}
private Android.Widget.Toolbar _topMenu;
private Adapter _adapter;
private ViewPager _pager;
private PagerSlidingTabStrip _tabs;
private RecyclerView _recyclerView;
private LayoutManager _layoutManager;
public string _tag = "MainActivity";
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
_recyclerView = FindViewById<RecyclerView>(Resource.Id.recyclerView);
_layoutManager = new LayoutManager(this, _recyclerView);
_layoutManager.addItem("one", "two", "three");
_layoutManager.addItem("one", "two", "three");
_layoutManager.createLayoutManager();
_adapter = new Adapter(SupportFragmentManager);
_pager = FindViewById<ViewPager>(Resource.Id.pager);
_tabs = FindViewById<PagerSlidingTabStrip>(Resource.Id.tabs);
_pager.Adapter = _adapter;
_tabs.SetViewPager(_pager);
_topMenu = FindViewById<Android.Widget.Toolbar>(Resource.Id.top_menu);
SetActionBar(_topMenu);
}
-
class LayoutManager
{
public RecyclerView _mRecyclerView;
public RecyclerView.LayoutManager _mLayoutManager;
public RecyclerView.Adapter _mAdapter;
public ItemList<Item> _mItems;
public Activity _main;
public LayoutManager(Activity main, RecyclerView recyclerView)
{
_main = main;
_mRecyclerView = recyclerView;
_mItems = new ItemList<Item>();
}
public void createLayoutManager()
{
_mLayoutManager = new LinearLayoutManager(_main);
_mRecyclerView.SetLayoutManager(_mLayoutManager);
_mAdapter = new RecyclerAdapter(_mItems, _mRecyclerView);
_mItems.Adapter = _mAdapter;
_mRecyclerView.SetAdapter(_mAdapter);
}
public void addItem(string name, string brand, string description)
{
_mItems.Add(new Item()
{
Img = Resource.Drawable.Icon,
Name = name,
Brand = brand,
Desciption = description
});
}
}
在这一行中（在我的 LayoutManager.cs 中）：
_mRecyclerView.SetLayoutManager(_mLayoutManager);
我有这个错误：
System.NullReferenceException: Object reference not set to an instance of an object.
我不明白问题的价值是什么？ 我忘记了什么？ 我完全迷路了？ 请..帮助！
谢谢你， 罗曼
【问题讨论】：
标签： xamarin android-recyclerview xamarin.android pagerslidingtabstrip