在 WPF 中将 DataGrid 数据分组到两个子级别扩展器中答案

【问题标题】：Grouping DataGrid data into two sub levels expanders in WPF在 WPF 中将 DataGrid 数据分组到两个子级别扩展器中
【发布时间】：2020-12-17 02:32:07
【问题描述】：

我想用两个级别的扩展器对我的数据进行分组，内部扩展器应该包含一个绑定到 List 的数据网格主要绑定类：

public class BudgetProposalViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public BudgetProposal Proposal { get; set; }

    public BudgetProposalViewModel(BudgetProposal proposal)
    {
        Proposal = proposal;
    }

    public ObservableCollection<PhaseCategory> Categories
    {
        get => new ObservableCollection<PhaseCategory>(Proposal.Phases);
        set
        {
            Proposal.Phases = value.ToList();
            OnPropertyChanged();
        }
    }

public class BudgetProposal
{
    public string Name { get; set; }
    public List<PhaseCategory> Phases { get; set; }
}

public class PhaseCategory
{
    public string Name { get; set; }
    public List<PhaseSubCategory> SubCategories { get; set; }
}

public class PhaseSubCategory 
{
    public string Name { get; set; }
    public List<Task> Tasks { get; set; }
}

public class Task
{
    public string Name { get; set; }
    public DepartmentsValues DepartmentsContribution { get; set; }
    public Task(string name, DepartmentsValues departmentsContribution)
    {
        Name = name;
        DepartmentsContribution = departmentsContribution;
    }
}

public class DepartmentsValues
{
    public double Civil { get; set; }
    public double Arch { get; set; }
    public double Mech{ get; set; }
    public DepartmentsValues(double civil, double arch, double mech)
    {
        Civil = civil;
        Arch = arch;
        Mech = mech;
    }
}

这是我正在使用的测试对象

public partial class MainWindow
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext=new BudgetProposalViewModel(new BudgetProposal("Test Proposal", 
            new List<PhaseCategory>()
            {
                new PhaseCategory("Category 1", 
                    new List<PhaseSubCategory>
                    {
                        new PhaseSubCategory("Sub Category 1",
                            new List<Task>
                            {
                                new Task("Task 1",new DepartmentsValues(1,2,3)),
                                new Task("Task 2",new DepartmentsValues(1,2,3)
                               )
                            }),
                        new PhaseSubCategory("Sub Category 2",
                            new List<Task>
                            {
                                new Task("Task 3",new DepartmentsValues(1,2,3)
                                )
                            })
                    }),

                new PhaseCategory("Category 2",
                    new List<PhaseSubCategory>
                    {
                        new PhaseSubCategory("Sub Category 3",
                            new List<Task>
                            {
                                new Task("Task 4",new DepartmentsValues(1,2,3)
                                )
                            })
                    }),

            }){});
    }
}

我尝试在 XAML 中执行以下操作，但内部扩展器不显示数据

<Grid d:DataContext="{d:DesignData BudgetProposalViewModel}">
        <Grid.Resources>
            <CollectionViewSource x:Key="groups" Source="{Binding Categories}">
                <CollectionViewSource.GroupDescriptions>
                    <PropertyGroupDescription PropertyName="Name" />
                </CollectionViewSource.GroupDescriptions>
            </CollectionViewSource>
        </Grid.Resources>
        <DataGrid x:Name="GridProposalCategories" ItemsSource="{Binding Source={StaticResource groups}}" AutoGenerateColumns="False">
            <DataGrid.GroupStyle>
                <GroupStyle>
                    <GroupStyle.ContainerStyle>
                        <Style TargetType="{x:Type GroupItem}" BasedOn="{StaticResource MahApps.Styles.GroupItem.DataGrid}">
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type GroupItem}">
                                        <Expander IsExpanded="True" d:DataContext="{d:DesignData PhaseCategory}">
                                            <Expander.Header>
                                                <DockPanel>
                                                    <TextBlock Text="{Binding Path=Name}" />
                                                </DockPanel>
                                            </Expander.Header>
                                            <Expander.Content>
                                                <Expander IsExpanded="True" d:DataContext="{d:DesignData PhaseSubCategory}">
                                                    <Expander.Header>
                                                        <DockPanel>
                                                            <TextBlock Text="{Binding Path=Items[0].Name}" />
                                                        </DockPanel>
                                                    </Expander.Header>
                                                    <Expander.Content>
                                                        <DataGrid ItemsSource="{Binding Path=Items[0].Tasks}" AutoGenerateColumns="True"></DataGrid>

                                                    </Expander.Content>
                                                </Expander>
                                            </Expander.Content>
                                        </Expander>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </GroupStyle.ContainerStyle>
                </GroupStyle>
            </DataGrid.GroupStyle>
        </DataGrid>
    </Grid>

我的数据绑定出了什么问题？output grid

【问题讨论】：

标签： c# wpf xaml

【解决方案1】：

内部扩展不显示数据，因为您对设计 DataContext 做出了错误的假设。它不是 PhaseSubCategory，它仍然是 PhaseCategory。将最后一个 DataGrid 更改为 Items[0].SubCategories 而不是 Items[0].Tasks，它会显示出来。

<Expander.Content>
    <Expander IsExpanded="True" d:DataContext="{d:DesignData PhaseSubCategory}">
        <Expander.Header>
            <DockPanel>
                <TextBlock Text="{Binding Path=Items[0].Name}" />
            </DockPanel>
        </Expander.Header>
        <Expander.Content>
            <DataGrid ItemsSource="{Binding Path=Items[0].SubCategories}" AutoGenerateColumns="True"></DataGrid>
        </Expander.Content>
    </Expander>
</Expander.Content>

【讨论】：