我有两个简单的 Model 类和一个 ViewModel...
public class GridItem
{
public string Name { get; set; }
public int CompanyID { get; set; }
}
public class CompanyItem
{
public int ID { get; set; }
public string Name { get; set; }
}
public class ViewModel
{
public ViewModel()
{
GridItems = new ObservableCollection<GridItem>() {
new GridItem() { Name = "Jim", CompanyID = 1 } };
CompanyItems = new ObservableCollection<CompanyItem>() {
new CompanyItem() { ID = 1, Name = "Company 1" },
new CompanyItem() { ID = 2, Name = "Company 2" } };
}
public ObservableCollection<GridItem> GridItems { get; set; }
public ObservableCollection<CompanyItem> CompanyItems { get; set; }
}
...和一个简单的窗口:
<Window x:Class="DataGridComboBoxColumnApp.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<DataGrid AutoGenerateColumns="False" ItemsSource="{Binding GridItems}" >
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Name}" />
<DataGridComboBoxColumn ItemsSource="{Binding CompanyItems}"
DisplayMemberPath="Name"
SelectedValuePath="ID"
SelectedValueBinding="{Binding CompanyID}" />
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
ViewModel 设置为 App.xaml.cs 中 MainWindow 的 DataContext
:
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
MainWindow window = new MainWindow();
ViewModel viewModel = new ViewModel();
window.DataContext = viewModel;
window.Show();
}
}
如您所见,我将 DataGrid 的 ItemsSource
设置为 ViewModel 的 GridItems
集合。这部分有效,显示了名为“Jim”的单条网格线。
我还想将每行中 ComboBox 的 ItemsSource
设置为 ViewModel 的 CompanyItems
集合。这部分不起作用:组合框保持为空,并且在调试器输出窗口中我看到一条错误消息:
System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=CompanyItems; DataItem=null; target element is 'DataGridComboBoxColumn' (HashCode=28633162); target property is 'ItemsSource' (type 'IEnumerable')
我相信 WPF 期望 CompanyItems
是 GridItem
的属性,但事实并非如此,这就是绑定(bind)失败的原因。
我已经尝试过使用 RelativeSource
和 AncestorType
,如下所示:
<DataGridComboBoxColumn ItemsSource="{Binding CompanyItems,
RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType={x:Type Window}}}"
DisplayMemberPath="Name"
SelectedValuePath="ID"
SelectedValueBinding="{Binding CompanyID}" />
但这在调试器输出中给了我另一个错误:
System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Window', AncestorLevel='1''. BindingExpression:Path=CompanyItems; DataItem=null; target element is 'DataGridComboBoxColumn' (HashCode=1150788); target property is 'ItemsSource' (type 'IEnumerable')
问题:如何将 DataGridComboBoxColumn 的 ItemsSource 绑定(bind)到 ViewModel 的 CompanyItems 集合?这可能吗?
感谢您提前提供帮助!
最佳答案
请检查下面的 DataGridComboBoxColumn xaml 是否适合您:
<DataGridComboBoxColumn
SelectedValueBinding="{Binding CompanyID}"
DisplayMemberPath="Name"
SelectedValuePath="ID">
<DataGridComboBoxColumn.ElementStyle>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="ItemsSource" Value="{Binding Path=DataContext.CompanyItems, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" />
</Style>
</DataGridComboBoxColumn.ElementStyle>
<DataGridComboBoxColumn.EditingElementStyle>
<Style TargetType="{x:Type ComboBox}">
<Setter Property="ItemsSource" Value="{Binding Path=DataContext.CompanyItems, RelativeSource={RelativeSource AncestorType={x:Type Window}}}" />
</Style>
</DataGridComboBoxColumn.EditingElementStyle>
</DataGridComboBoxColumn>
在这里您可以找到解决您所面临问题的另一种解决方案:Using combo boxes with the WPF DataGrid
关于.net - 在 WPF DataGrid 中绑定(bind) ComboBoxColumn 的 ItemsSource,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/5409259/