Question

在我的WP8.1（WinRT）应用程序中，我有一个listview控件，其中的分组定义了数据绑定。但是当我运行应用程序时，我没有看到任何数据项或任何绑定错误。

我无法弄清楚错误是什么。这是我的XAML和代码，以及如何将其扩展到跳转列表？

我的xaml

   <DataTemplate x:Key="DataTemplate1">
        <StackPanel VerticalAlignment="Top">
            <TextBlock Text="{Binding Name}" FontSize="26"  Margin="12,-12,12,6"/>
            <TextBlock Text="{Binding Country}"  Foreground="GreenYellow"/>
            <TextBlock Text="{Binding Language}" Foreground="Orange" />
        </StackPanel>
    </DataTemplate>
    <DataTemplate x:Key="GroupHeader">
        <Border Background="Transparent">
            <Border Background="Transparent" BorderBrush="Transparent" BorderThickness="1"  
                    Width="400" Height="90" HorizontalAlignment="Left">
                <TextBlock Text="{Binding Key}" 
                           Foreground="{StaticResource PhoneAccentBrush}" 
                           FontSize="28"
                           Padding="2"                                
                           FontFamily="{StaticResource PhoneFontFamilySemiLight}"
                           HorizontalAlignment="Left"
                           VerticalAlignment="Center"/>
            </Border>
        </Border>

<Grid>
    <Grid.DataContext>
        <testApp:DemoViewModel/>
    </Grid.DataContext>
    <ListView x:Name="CitiesList" ItemTemplate="{StaticResource DataTemplate1}" ItemsSource="{Binding CityByCountry}">
        <ListView.GroupStyle>
            <GroupStyle HidesIfEmpty="True" HeaderTemplate="{StaticResource GroupHeader}" />
        </ListView.GroupStyle>
    </ListView>
</Grid>

和我的c＃（Model，ViewModel）

public class DemoViewModel
{
    public List<KeyedList<string, City>> CityByCountry { get; set; }
}

public class KeyedList<TKey, TItem> : List<TItem>
{
    public TKey Key { protected set; get; }

    public KeyedList(TKey key, IEnumerable<TItem> items): base(items)
    {
        Key = key;
    }

    public KeyedList(IGrouping<TKey, TItem> grouping): base(grouping)
    {
        Key = grouping.Key;
    }
}
public class City
{
    public string Name { get; set; }
    public string Country { get; set; }
    public string Language { get; set; }
}

我使用下面的代码加载demodata以便在主页面中进行测试

       List<City> source = new List<City>
        {
            new City {Name = "Madrid", Country = "ES", Language = "Spanish"},
            new City {Name = "Barcelona", Country = "ES", Language = "Spanish"},
            new City {Name = "Mallorca", Country = "ES", Language = "Spanish"},
            new City {Name = "Las Vegas", Country = "US", Language = "English"},
            new City {Name = "Dalas", Country = "US", Language = "English"},
            new City {Name = "New York", Country = "US", Language = "English"},
            new City {Name = "London", Country = "UK", Language = "English"},
            new City {Name = "Mexico", Country = "MX", Language = "Spanish"},
            new City {Name = "Milan", Country = "IT", Language = "Italian"},
            new City {Name = "Roma", Country = "IT", Language = "Italian"},
            new City {Name = "Paris", Country = "FR", Language = "French"}
        };

        // this.citiesList.ItemsSource = source;
        DemoViewModel viewModel = new DemoViewModel();
        var tmp = from city in source
                  group city by city.Country into c
                  orderby c.Key
                  select new KeyedList<string, City>(c.Key, c);

        viewModel.CityByCountry = new List<KeyedList<string, City>>(tmp);
        DataContext = viewModel;

Answer 1

您必须使用CollectionViewSource进行分组。希望这可以帮助你Jumplists in Windows Phone 8.1 (Updated)

并将您的tmp设置为Source

带分组的ListView未显示任何项目

1 个答案: