wpf Xamarin 表单列表视图数据绑定
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Xamarin Forms listview databinding
提问by Guido Magrin
I am currently following this guide:
我目前正在遵循本指南：
http://www.morganskinner.com/2015/01/xamarin-forms-contacts-search.html
http://www.morganskinner.com/2015/01/xamarin-forms-contacts-search.html
I am willing to make a contacts page in my app, like the one showed in the pictures there, still something is not working out as it should for me:
我愿意在我的应用程序中创建一个联系人页面，就像那里的图片中显示的那样，但仍有一些事情没有像我应该的那样工作：
I wrote/copied the XAML:
我编写/复制了 XAML：
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<SearchBar x:Name="search" Placeholder="Search"/>
<ListView x:Name="ProvaView" Grid.Row="1" ItemsSource="{Binding FilteredContacts}" IsGroupingEnabled="true" GroupDisplayBinding="{Binding Key}" GroupShortNameBinding="{Binding Key}">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding Name}" TextColor="Black" Detail="{Binding PhoneNumber}" DetailColor="Gray">
</TextCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
and now I am trying to "display something", not dinamically loaded (yet), from a list of data.
现在我试图从数据列表中“显示一些东西”，而不是动态加载（还）。
I declared a class like this:
我声明了一个这样的类：
public class Contact
{
public string Name { get; set; }
public string PhoneNumber { get; set; }
}
}
and now the code behind the xaml is this:
现在 xaml 背后的代码是这样的：
public partial class ContactsPage : MasterDetailPage
{
public List<Contact> FilteredContacts = new List<Contact>
{
new Contact
{
Name = "Guido",
PhoneNumber = "3292773477"
},
new Contact
{
Name = "Luca",
PhoneNumber = "3472737445"
},
new Contact
{
Name = "Luca",
PhoneNumber = "3472737445"
}
};
public ContactsPage()
{
InitializeComponent();
ProvaView.ItemsSource = FilteredContacts;
}
}
When I launch the app, all I get anyway is an empty listview, with 3 fields but nothing in it.
当我启动应用程序时，我得到的只是一个空的列表视图，有 3 个字段，但没有任何内容。
Where am I doing wrong?
我哪里做错了？
Also, straight from the page where I am working off, I can't understand the meaning of these Fields associated to the listview:
此外，直接从我正在处理的页面中，我无法理解与列表视图相关的这些字段的含义：
GroupDisplayBinding="{Binding Key}" GroupShortNameBinding="{Binding Key}"
GroupDisplayBinding="{Binding Key}" GroupShortNameBinding="{Binding Key}"
and as much as I could look around on the web, I coudln't find any reference to both of them.
尽我所能在网上环顾四周，我找不到任何关于他们两个的参考。
回答by Toni Petrina
Most likely the problem is with the way you declared FilteredContacts, it should be a property, and not a field. The reflection mechanism used in binding only searches for properties, fields are not included.
问题很可能出在您声明的方式上FilteredContacts，它应该是一个属性，而不是一个字段。绑定中使用的反射机制仅搜索属性，不包括字段。
