如何在WPF DataGrid中定义自己的列？

Question

我有一个AutoGenerateColumnsWPF-DataGrid绑定到LINQ-to-SQL的代码隐藏,这很好.

但是当我取消AutoGenerateColumns并定义我自己的列时,它告诉我" 在使用ItemsSource之前,items集合必须为空 ".

但是我没有绑定ItemSource我的XAML所以我不明白为什么它不是空的.我需要更改什么才能定义自己的列？

XAML:

<UserControl x:Class="TestDataGrid566.AppPages.ManageCustomers"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:toolkit="http://schemas.microsoft.com/wpf/2008/toolkit"
             Loaded="UserControl_Loaded">
    <toolkit:DataGrid x:Name="TheDataGrid" 
                      CanUserAddRows="False"
                      AlternatingRowBackground="#ddd"
                      CanUserSortColumns="true"
                      PreviewKeyDown="TheDataGrid_PreviewKeyDown"
                      AutoGenerateColumns="False"
                      RowEditEnding="TheDataGrid_RowEditEnding">

        <toolkit:DataGridTextColumn Header="Contact Name" Width="SizeToCells"  
                                    Binding="{Binding ContactName}" 
                                    IsReadOnly="False"/>
    </toolkit:DataGrid>
</UserControl>

后台代码:

public partial class ManageCustomers : UserControl
{
    private NorthwindDataContext _db = new NorthwindDataContext();

    public ManageCustomers()
    {
        InitializeComponent();
    }

    private void UserControl_Loaded(object sender, RoutedEventArgs e)
    {
        LoadData();
    }

    public void LoadData()
    {
        var customers = from c in _db.Customers
                        select c;
        TheDataGrid.ItemsSource = customers.ToList();
    }
}

Answer 1

你试图将列直接放入DataGrid(因此它试图将列放在网格的Items集合中,这解释了你的错误).你需要把它放在Columns集合中:

<toolkit:DataGrid x:Name="TheDataGrid" 
                          CanUserAddRows="False"
                          AlternatingRowBackground="#ddd"
                          CanUserSortColumns="true"
                          PreviewKeyDown="TheDataGrid_PreviewKeyDown"
                          AutoGenerateColumns="False"
                          RowEditEnding="TheDataGrid_RowEditEnding">
    <toolkit:DataGrid.Columns>        
        <toolkit:DataGridTextColumn Header="Contact Name" Width="SizeToCells"  
                                       Binding="{Binding ContactName}" 
                                       IsReadOnly="False"/>
    </toolkit:DataGrid.Columns>
</toolkit:DataGrid>