从两个表中检索数据并填充 DataGrid 实体框架

Question

我正在使用实体框架。我的数据库客户和发票中有 2 个表。发票表有一列 CustomerID 作为外键引用客户。我正在使用DataGrid具有以下列的一个，如图所示。这DataGrid应该显示来自发票表的数据和来自客户表的客户名称。请帮我如何查询这个？数据网格<DataGrid IsReadOnly="False" Margin="0 10 0 0" Background="white" Name="InvoiceGrid" AutoGenerateColumns="False">    <DataGrid.Columns>        <DataGridTextColumn Header="Invoice ID" IsReadOnly="True" MinWidth="100"/>        <DataGridTextColumn Header="Date" IsReadOnly="True" MinWidth="100" />        <DataGridTextColumn Header="Customer" IsReadOnly="True" MinWidth="250" />        <DataGridTextColumn Header="Quantity" IsReadOnly="True" MinWidth="80" />        <materialDesign:MaterialDataGridTextColumn IsReadOnly="True" Header="Total" MinWidth="150" />  上下文类public partial class Intelliventory_DBEntities : DbContext{    public Intelliventory_DBEntities()        : base("name=Intelliventory_DBEntities")    {    }    protected override void OnModelCreating(DbModelBuilder modelBuilder)    {        throw new UnintentionalCodeFirstException();    }    public virtual DbSet<Category> Categories { get; set; }    public virtual DbSet<Customer> Customers { get; set; }    public virtual DbSet<Employee> Employees { get; set; }    public virtual DbSet<Invoice> Invoices { get; set; }    public virtual DbSet<InvoiceItem> InvoiceItems { get; set; }    public virtual DbSet<Product> Products { get; set; }    public virtual DbSet<Purchase> Purchases { get; set; }    public virtual DbSet<Supplier> Suppliers { get; set; }    public virtual DbSet<sysdiagram> sysdiagrams { get; set; }}

Answer 1

如果Customer是 的导航属性Invoice，您可以使用预先加载来加载它，例如：

var context = new Intelliventory_DBEntities();

InvoiceGrid.ItemsSource = context.Invoices.Include(x => x.Customer).ToList();

//...

context.Dispose();

然后，您可以将该列绑定到导航属性：

<DataGridTextColumn Header="Invoice ID" Binding="{Binding InvoiceID}" IsReadOnly="True" MinWidth="100"/>

<DataGridTextColumn Header="Date" Binding="{Binding Date}" IsReadOnly="True" MinWidth="100" />

<DataGridTextColumn Header="Customer" Binding="{Binding Customer.CustomerName}" IsReadOnly="True" MinWidth="250" />