Question

我有一个[表格] Book，其中列为[列] Title | Author | Editor | Genre

我使用Pivot模板，标题为Title，Author，Editor，Genre。示例：我有3本书：

1 / Title =“ABC”|作者=“约翰”|编辑=“杰瑞”|类型=“小说”

2 / Title =“EFH”|作者=“约翰”|编辑=“哈利”|类型=“神秘”

3 / Title =“HJK”|作者=“汤姆”|编辑=“杰瑞”|类型=“神秘”

我想要的是每个标题只显示：

标题标题中的

：ABC | EFH | HJK

在作者标题中的

只显示：John | Tom

编辑器标题中的

只显示：Jerry | Harry

Genre标题中的

只显示：Novel | Mystery

代码：

 <!--Book-->
        <controls:PivotItem Header="Book">
            <Grid x:Name="ContentPanel1" Margin="12,0,12,0">
                <ListBox x:Name="TitleList" SelectionChanged="TitleList_SelectionChanged" ItemsSource="{Binding Data}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid Width="466" Margin="0, 0, 0, 12">
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="10"/>
                                    <ColumnDefinition Width="360"/>
                                    <ColumnDefinition Width="Auto"/>
                                </Grid.ColumnDefinitions>
                                <Grid Grid.Column="0"></Grid>
                                <StackPanel Grid.Column="1">
                                    <TextBlock FontSize="40"   Text="{Binding BookTitle}" FontWeight="Normal" FontStyle="Normal" Style="{StaticResource PhoneTextTitle3Style}" TextWrapping="Wrap"/>
                                </StackPanel>
                                <Grid Grid.Column="2">
                                    <Button x:Name="Deletebutton" Height="60" Width="60" Click="deleteButton_Click" BorderBrush="{StaticResource TransparentBrush}">
                                     <Image Source="/Assets/delete.dark.png" Visibility="{StaticResource PhoneDarkThemeVisibility}" Margin="-25" HorizontalAlignment="Left"/>
                                    </Button>
                                </Grid>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PivotItem>

        <!--Author-->
        <controls:PivotItem Header="Author">
            <Grid x:Name="ContentPanel2" Margin="12,0,12,0">
                <ListBox x:Name="AuthorList"  ItemsSource="{Binding Data}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock FontSize="40"   Text="{Binding Author}" FontWeight="Normal" FontStyle="Normal" Style="{StaticResource PhoneTextTitle3Style}" TextWrapping="Wrap"/>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PivotItem>

        <!--Editor-->
        <controls:PivotItem Header="Editor">
            <Grid x:Name="ContentPanel3" Margin="12,0,12,0">
                <ListBox x:Name="EditorList"  ItemsSource="{Binding Data}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock FontSize="40"   Text="{Binding Editor}" FontWeight="Normal" FontStyle="Normal" Style="{StaticResource PhoneTextTitle3Style}" TextWrapping="Wrap"/>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PivotItem>
        <!--Editor-->
        <controls:PivotItem Header="Editor">
            <Grid x:Name="ContentPanel4" Margin="12,0,12,0">
                <ListBox x:Name="BookImporterList"  ItemsSource="{Binding Data}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock FontSize="40"   Text="{Binding Editor}" FontWeight="Normal" FontStyle="Normal" Style="{StaticResource PhoneTextTitle3Style}" TextWrapping="Wrap"/>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PivotItem>
        <!--Genre-->
        <controls:PivotItem Header="Genre">
            <Grid x:Name="ContentPanel5" Margin="12,0,12,0">
                <ListBox x:Name="GenreList"  ItemsSource="{Binding Data}">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock FontSize="40"   Text="{Binding Genre}" FontWeight="Normal" FontStyle="Normal" Style="{StaticResource PhoneTextTitle3Style}" TextWrapping="Wrap"/>
                            </Grid>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </Grid>
        </controls:PivotItem>
    </controls:Pivot>

在我的MainViewModel中：

private ObservableCollection<Book> _load = new ObservableCollection<Book>();
public ObservableCollection<Book> Load
{
    get { return _load; }
    set
    {
        _load = value;
        NotifyPropertyChanged("Load");
    }
}
public void LoadData()
{
    var orderedGenre = (from Book b in BookDB.Books select b);
}

Answer 1

这是获得你想要的东西的一种可能方式。

在ViewModel中提供了一个存储所有Books的属性，在这种情况下它是Load属性。然后为要显示的每个Book的属性声明新属性。它们中的每一个都从相应的Book属性返回不同值的集合。在Load属性的setter中，我为从Load属性返回值的所有属性引发了PropertyChanged事件。

我在这里提供了两种方法，通过使用Distinct方法或使用GroupBy方法从Book的ObservableCollection中获取不同的值。但我更喜欢第一种方式，因为它在这种情况下更短/更简单。

private ObservableCollection<Book> _load = new ObservableCollection<Book>();
public ObservableCollection<Book> Load
{
    get { return _load; }
    set
    {
        _load = value;
        NotifyPropertyChanged("Load");
        NotifyPropertyChanged("Titles");
        NotifyPropertyChanged("Authors");
    }
}

public ObservableCollection<String> Titles
{
    get { return new ObservableCollection<string>(Load.Select(o => o.Title).Distinct()); }
    //get { return new ObservableCollection<string>(Load.GroupBy(o => o.Title).Select(o => o.Key)); }
}

public ObservableCollection<String> Authors
{
    get { return new ObservableCollection<string>(Load.Select(o => o.Author).Distinct()); }
    //get { return new ObservableCollection<string>(Load.GroupBy(o => o.Title).Select(o => o.Key)); }
}

public void LoadData()
{
    var orderedGenre = (from Book b in BookDB.Books select b);
    Load = new ObservableCollection<Book>(orderedGenre);
}

然后在XAML中，将每个ListBox的ItemsSource绑定到已在ViewModel中创建的相应属性：

<controls:PivotItem Header="Book">
    <Grid x:Name="ContentPanel1" Margin="12,0,12,0">
        <ListBox x:Name="TitleList" SelectionChanged="TitleList_SelectionChanged" ItemsSource="{Binding Titles}">
        ....

        ....
<controls:PivotItem Header="Author">
        <Grid x:Name="ContentPanel2" Margin="12,0,12,0">
            <ListBox x:Name="AuthorList"  ItemsSource="{Binding Authors}">
        ....

        ....

如何从Observablecollection中显示不同的值？

1 个答案: