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我在WPF MVVM應用程序中設置了Xceed數據網格，該應用程序設置爲保存主 - 細節記錄。當選擇一個子行時，我希望ViewModel檢測所選的子元素。我希望在零代碼隱藏的情況下執行此操作。我已經編寫了代碼，當單擊某個上下文菜單時，將對選定的項目執行操作。這可以在選擇父項時正常工作，但在選擇子項時總是返回null。Xceed Datagrid在子選擇時丟失SelectedItem
我已經把什麼我試圖acheive一個非常簡化的版本：
我的XAML是：
<Window x:Class="MasterDetailSelection.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:xcdg="clr-namespace:Xceed.Wpf.DataGrid;assembly=Xceed.Wpf.DataGrid.v4.2"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.Resources>
<xcdg:DataGridCollectionViewSource x:Key="cvs_parents" Source="{Binding Path=Parents}">
<xcdg:DataGridCollectionViewSource.DetailDescriptions>
<xcdg:PropertyDetailDescription RelationName="Children"
AutoCreateDetailDescriptions="False">
</xcdg:PropertyDetailDescription>
</xcdg:DataGridCollectionViewSource.DetailDescriptions>
</xcdg:DataGridCollectionViewSource>
</Grid.Resources>
<xcdg:DataGridControl x:Name="ParentGrid"
NavigationBehavior="RowOnly"
ItemsSource="{Binding Source={StaticResource cvs_parents}}"
SelectedItem="{Binding SelectedItem}"
AutoCreateDetailConfigurations="True"
ReadOnly="True">
<xcdg:DataGridControl.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Execute Command"
CommandParameter="{Binding DataContext.SelectedItem}"
Command="{Binding DataContext.SampleCommand}" />
</ContextMenu>
</xcdg:DataGridControl.ContextMenu>
</xcdg:DataGridControl>
</Grid>
</Window>
視圖模型是：
namespace MasterDetailSelection
{
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using Microsoft.Practices.Composite.Presentation.Commands;
public class ViewModel : INotifyPropertyChanged
{
private ObservableCollection<Parent> _parents;
public event PropertyChangedEventHandler PropertyChanged;
private DelegateCommand<Object> _sampleCommand;
private object _selectedItem;
public ObservableCollection<Parent> Parents
{
get { return _parents; }
set
{
_parents = value;
OnPropertyChanged("Parents");
}
}
public DelegateCommand<Object> SampleCommand
{
get
{
if (_sampleCommand == null)
{
_sampleCommand = new DelegateCommand<object>(ExecuteSampleCommand, CanExecuteSampleCommand);
OnPropertyChanged("SampleCommand");
}
return _sampleCommand;
}
}
public bool CanExecuteSampleCommand(Object commandParameter)
{
return true;
}
public void ExecuteSampleCommand(Object commandParameter)
{
Console.WriteLine("ExecuteSampleCommand");
}
public object SelectedItem
{
get { return _selectedItem; }
set
{
if (_selectedItem != value)
{
_selectedItem = value;
OnPropertyChanged("SelectedItem");
}
}
}
public void LoadParents()
{
var parents = new ObservableCollection<Parent>()
{
new Parent()
{
Id=1,
Description = "Parent1",
Children = new List<Child>(){new Child() {Id = 1, Description = "Child1"} }
}
};
Parents = parents;
}
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
有2簡單實體：
public class Parent
{
public int Id { get; set;}
public string Description { get; set;}
public IEnumerable<Child> Children { get; set;}
}
public class Child
{
public int Id { get; set; }
public string Description { get; set; }
}
在App.xaml.cs的OnStartup覆蓋包含以下內容：
var viewModel = new ViewModel();
var window = new MainWindow();
window.DataContext = viewModel;
viewModel.LoadParents();
window.Show();
每當我選擇父行中，二傳的SelectedItem被稱爲具有佔據的對象。當我選擇一個子行時，同一個setter被調用，但是有一個空值。
當在子行上單擊上下文菜單時，是否有任何方法可以獲取對所選項目的引用 - 並且在沒有代碼隱藏的情況下執行此操作。如果沒有，是否有可能使用代碼隱藏？