如何在 Xamarin Android 的 AlertDialog 中创建带有自定义适配器的列表视图
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【中文标题】如何在 Xamarin Android 的 AlertDialog 中创建带有自定义适配器的列表视图【英文标题】：How can I create a listview with custom adapter inside a AlertDialog in Xamarin Android 【发布时间】：2021-10-14 05:27:34 【问题描述】：我正在尝试在 Xamarin android 的 AllertDialog 中创建一个 ListView。
我已经搜索并找到了一些示例，但我没有找到任何使用 C# 在 AlertDialog 中使用 ListView 和自定义适配器的示例。
我找到的最接近的样本是下面的示例 (Thanks to Macoratti)。这个没有AlertDialog。 我已经尝试适应，但我得到 System.NullReferenceException: 'Object reference not set to an instance of an object.'.
主要活动：
namespace App.CustomAdapterListView
[Activity(Label = "App.CustomAdapterListView", MainLauncher = true, Icon = "@drawable/icon")]
public class MainActivity : Activity
protected override void OnCreate(Bundle bundle)
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
/* Original
var filmesListView = FindViewById<ListView>(Resource.Id.filmeslistView);
filmesListView.FastScrollEnabled = true;
filmesListView.ItemClick += FilmesListView_ItemClick;
var filmesAdapter = new FilmeAdapter(this, FilmesRepositorio.Filmes);
filmesListView.Adapter = filmesAdapter;
*/
var ViewAD = LayoutInflater.Inflate(Resource.Layout.Filmes, null);
AlertDialog alertDialog;
using (var dialog = new AlertDialog.Builder(this))
dialog.SetView(ViewAD);
dialog.SetNegativeButton("Cancel", (s, a) => );
alertDialog = dialog.Create();
var adapter = new FilmeAdapter(this, FilmesRepositorio.Filmes);
// Here I get - System.NullReferenceException: 'Object reference not set to an instance of an object.'
ViewAD.FindViewById<ListView>(Resource.Id.filmeslistView).Adapter = adapter;
alertDialog.Show();
private void FilmesListView_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
Toast.MakeText(this, FilmesRepositorio.Filmes[e.Position].ToString(), ToastLength.Long).Show();
适配器类：
namespace App.CustomAdapterListView
public class Filme
public int Id get; set;
public string Titulo get; set;
public string Diretor get; set;
public DateTime DataLancamento get; set;
public override string ToString()
return Titulo + " por " + Diretor;
适配器：
namespace App.CustomAdapterListView
public class FilmeAdapter : BaseAdapter<Filme>
private readonly Activity context;
private readonly List<Filme> filmes;
public FilmeAdapter(Activity context, List<Filme> filmes)
this.context = context;
this.filmes = filmes;
public override Filme this[int position]
get
return filmes[position];
public override int Count
get
return filmes.Count;
public override long GetItemId(int position)
return filmes[position].Id;
public override View GetView(int position, View convertView, ViewGroup parent)
var view = convertView ?? context.LayoutInflater.Inflate(Resource.Layout.Filmes, parent, false);
var txtTitulo = view.FindViewById<TextView>(Resource.Id.tituloTextView);
var txtDiretor = view.FindViewById<TextView>(Resource.Id.diretorTextView);
var txtLancamento = view.FindViewById<TextView>(Resource.Id.dataLancamentoTextView);
txtTitulo.Text = filmes[position].Titulo;
txtDiretor.Text = "Dirigido por: " + filmes[position].Diretor;
txtLancamento.Text = "Lançado em : " + filmes[position].DataLancamento.ToShortDateString();
return view;
数据库：
namespace App.CustomAdapterListView
public static class FilmesRepositorio
public static List<Filme> Filmes get; private set;
static FilmesRepositorio()
Filmes = new List<Filme>();
for (int i = 0; i < 10; i++)
AddFilmes();
private static void AddFilmes()
Filmes.Add(new Filme
Id = 1,
Titulo = "A New Hope",
Diretor = "George Lucas",
DataLancamento = new DateTime(1977, 05, 25)
);
Filmes.Add(new Filme
Id = 2,
Titulo = "The Empire Strikes Back",
Diretor = "George Lucas",
DataLancamento = new DateTime(1980, 05, 17)
);
Filmes.Add(new Filme
Id = 3,
Titulo = "O Reterono de Jedi",
Diretor = "George Lucas",
DataLancamento = new DateTime(1983, 05, 25)
);
Filmes.Add(new Filme
Id = 4,
Titulo = "A ameaça fantasma",
Diretor = "George Lucas",
DataLancamento = new DateTime(1999, 05, 19)
);
Filmes.Add(new Filme
Id = 5,
Titulo = "A vingança dos Sith",
Diretor = "George Lucas",
DataLancamento = new DateTime(2005, 05, 19)
);
Filmes.Add(new Filme
Titulo = "Marte",
Diretor = "J.J. Abrams",
DataLancamento = new DateTime(2015, 12, 11)
);
主布局 axml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_
android:layout_
android:minWidth="25px"
android:minHeight="25px">
<ListView
android:minWidth="25px"
android:minHeight="25px"
android:background="#eee5d5"
android:layout_
android:layout_
android:id="@+id/filmeslistView" />
</LinearLayout>
ListView的自定义布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_
android:layout_
android:padding="8dp">
<TextView
android:id="@+id/tituloTextView"
android:layout_
android:layout_
android:textColor="#000000"
android:textSize="20dp"
android:textStyle="bold"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/diretorTextView"
android:layout_
android:layout_
android:textColor="#00A14B"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/dataLancamentoTextView"
android:layout_
android:layout_
android:textColor="#7F3F97"
android:paddingLeft="5dp" />
</LinearLayout>
对不起，菜鸟问题。 我将不胜感激。
谢谢
【问题讨论】：
Resource.Layout.Filmes 是否包含Resource.Id.filmeslistView？
我不确定哪个是哪个，但是您为AlertDialog 的内容和Adapter 中的各个行添加了相同的布局：Resource.Layout.Filmes。
【参考方案1】：
您应该为包含ListView 的视图创建一个xml (dialogview.xml)，并为列表视图的每个项目创建一个xml (itemview.xml)。
例如：
创建一个dialogview.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_
android:layout_
android:minWidth="25px"
android:minHeight="25px">
<ListView
android:minWidth="25px"
android:minHeight="25px"
android:background="#eee5d5"
android:layout_
android:layout_
android:id="@+id/filmeslistView" />
</LinearLayout>
创建一个itemview.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_
android:layout_
android:padding="8dp">
<TextView
android:id="@+id/tituloTextView"
android:layout_
android:layout_
android:textColor="#000000"
android:textSize="20dp"
android:textStyle="bold"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/diretorTextView"
android:layout_
android:layout_
android:textColor="#00A14B"
android:paddingLeft="5dp" />
<TextView
android:id="@+id/dataLancamentoTextView"
android:layout_
android:layout_
android:textColor="#7F3F97"
android:paddingLeft="5dp" />
</LinearLayout>
在您的 MainActivity 中：
protected override void OnCreate(Bundle bundle)
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
var ViewAD = LayoutInflater.Inflate(Resource.Layout.dialogview, null);
var adapter = new FilmeAdapter(this, FilmesRepositorio.Filmes);
ViewAD.FindViewById<ListView>(Resource.Id.filmeslistView).Adapter = adapter;
AlertDialog alertDialog;
using (var dialog = new AlertDialog.Builder(this))
dialog.SetView(ViewAD);
dialog.SetNegativeButton("Cancel", (s, a) => );
alertDialog = dialog.Create();
alertDialog.Show();
在你的适配器中：
namespace App.CustomAdapterListView
public class FilmeAdapter : BaseAdapter<Filme>
private readonly Activity context;
private readonly List<Filme> filmes;
public FilmeAdapter(Activity context, List<Filme> filmes)
this.context = context;
this.filmes = filmes;
public override Filme this[int position]
get
return filmes[position];
public override int Count
get
return filmes.Count;
public override long GetItemId(int position)
return filmes[position].Id;
public override View GetView(int position, View convertView, ViewGroup parent)
var view = convertView ?? context.LayoutInflater.Inflate(Resource.Layout.itemview, parent, false);// inflate the xml for each item
var txtTitulo = view.FindViewById<TextView>(Resource.Id.tituloTextView);
var txtDiretor = view.FindViewById<TextView>(Resource.Id.diretorTextView);
var txtLancamento = view.FindViewById<TextView>(Resource.Id.dataLancamentoTextView);
txtTitulo.Text = filmes[position].Titulo;
txtDiretor.Text = "Dirigido por: " + filmes[position].Diretor;
txtLancamento.Text = "Lançado em : " + filmes[position].DataLancamento.ToShortDateString();
return view;
更新
var ViewAD = LayoutInflater.Inflate(Resource.Layout.dialogview, null);
var adapter = new FilmeAdapter(this, FilmesRepositorio.Filmes);
ListView listview = ViewAD.FindViewById<ListView>(Resource.Id.filmeslistView);
listview.Adapter = adapter;
listView.ItemClick += ListView_ItemClick;
...
private void ListView_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
//you could get the select data
【讨论】：
非常感谢 Leo，它有效。可悲的是，我还不能在你的回答中投票。如何将选定的值传递给 main，关闭警报对话框？ @nmend 你可以在列表视图中添加一个点击事件。我在上面更新它。 太完美了！你太棒了！以上是关于如何在 Xamarin Android 的 AlertDialog 中创建带有自定义适配器的列表视图的主要内容，如果未能解决你的问题，请参考以下文章
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