RowDetailsTemplate ItemSource绑定到EF NavigationProperty [英] RowDetailsTemplate ItemSource Binded to an EF NavigationProperty

问题描述

我有一个 DataGrid 的 Person 对象与另一个 DataGrid 在其 RowDetailsTemplate 中包含所选人员的作业，我使用 EntityFramework 来生成 DataContext ，每个人至少有一个作业（所以Person包含另一个类型为 PersonWork 的对象的外键）。
为了将 RowDetails DataGrid 与 selectedPerson的工作，我已将其（RowDetailsTemplate） itemSource 绑定到 Person 类的导航属性由EF生成），但$ code> RowDetails Grid始终为空！ （当我使用包含记录的立即窗口检查 SelectedPerson.PersonWork ）

I have a DataGrid of Person objects with another DataGrid in its RowDetailsTemplate which contains the selected person's Jobs, I am using EntityFramework to generate the DataContext, each person has a least one job (so Person contains a foreign key to another object of type PersonWork). In order to populate the RowDetails DataGrid with the selectedPerson's works, I've bind its (the RowDetailsTemplate) itemSource to the navigation property of the Person class (generated by EF), but the RowDetails Grid is always empty! (when i inspect the SelectedPerson.PersonWork using the immediate window it contains records)

这里 Xaml 我使用的代码：

<DataGrid Style="{StaticResource DataGridStyle}"  AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding ListPersons}" SelectedItem="{Binding SelectedPerson,Mode=TwoWay}"  >
            <DataGrid.Columns>
                <DataGridTextColumn Binding="{Binding PersonName}" Header="Name" Width="SizeToHeader" MinWidth="100"/>
                <DataGridTextColumn Binding="{Binding PersonAge}" Header="Age" Width="SizeToHeader" MinWidth="100"/>
            </DataGrid.Columns>
            <DataGrid.RowDetailsTemplate>
                <DataTemplate >
                    <DataGrid Height="100" AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding Path=SelectedPerson.PersonWorks}">
                        <DataGrid.Columns>
                            <DataGridTextColumn Binding="{Binding WorkID}" Header="WorkID" Width="SizeToHeader" MinWidth="100"/>
                            <DataGridTextColumn Binding="{Binding WorkTitle}" Header="Title" Width="SizeToHeader" MinWidth="100"/>
                            <DataGridTextColumn Binding="{Binding WorkRecommandation}" Header="Recommandation" Width="SizeToHeader" MinWidth="300"/>                              
                        </DataGrid.Columns>
                    </DataGrid>   
                </DataTemplate>
            </DataGrid.RowDetailsTemplate>
        </DataGrid>

而EF生成的类人员如下所示：

And The Class Person generated by EF looks like so:

public partial class Person
{
    public Person()
    {
        this.PersonWorks = new HashSet<PersonWorks>();
    }

    public long PersonId { get; set; }
    public string PersonName { get; set; }
    public long PersonAge { get; set; }

    public virtual ICollection<PersonWork> PersonWorks { get; set; }
}

Ps：我正在使用EF 6.1.1

Ps: I am using EF 6.1.1

更新
ListPersons是一个 ObservableCollection ，它像这样实例化：

Update The ListPersons is an ObservableCollectionand it is instantiated like so :

var _dbContext=new DBEntities();
ListPersons= new ObservableCollection<Person>(_dbContext.Persons);

推荐答案

为了达到这一点，你还必须指定DataContext在内部DataGrid中，或者使用ElementName直接从Main DataGrid获取内部的DataGrid Navigation属性集合，以下代码完美地工作：

In order to achieve that you must also specify the DataContext in inner DataGrid or get the inner DataGrid Navigation property collection directly from the Main DataGrid using the ElementName, the following code work perfectly :

<DataGrid x:Name="DataGrid" Style="{StaticResource DataGridStyle}"  AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding ListPersons}" SelectedItem="{Binding SelectedPerson,Mode=TwoWay}"  >
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding PersonName}" Header="Name" Width="SizeToHeader" MinWidth="100"/>
            <DataGridTextColumn Binding="{Binding PersonAge}" Header="Age" Width="SizeToHeader" MinWidth="100"/>
        </DataGrid.Columns>
        <DataGrid.RowDetailsTemplate>
            <DataTemplate >
                <DataGrid Height="100" AutoGenerateColumns="False" EnableRowVirtualization="True" ItemsSource="{Binding Path=SelectedItem.PersonWorks, ElementName=DataGrid}">
                    <DataGrid.Columns>
                        <DataGridTextColumn Binding="{Binding WorkID}" Header="WorkID" Width="SizeToHeader" MinWidth="100"/>
                        <DataGridTextColumn Binding="{Binding WorkTitle}" Header="Title" Width="SizeToHeader" MinWidth="100"/>
                        <DataGridTextColumn Binding="{Binding WorkRecommandation}" Header="Recommandation" Width="SizeToHeader" MinWidth="300"/>                              
                    </DataGrid.Columns>
                </DataGrid>   
            </DataTemplate>
        </DataGrid.RowDetailsTemplate>
    </DataGrid>

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