ContractListUserControl.XAML
<DataGrid AutoGenerateColumns="False"
ItemsSource="{Binding Path=ContractList}"
SelectedItem="{Binding Path=SelectedContract}">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Path=Person.LastName}" Header="Last Name" />
<DataGridTextColumn Binding="{Binding Path=Person.GivenName}" Header="Given Name" />
<DataGridTextColumn Binding="{Binding Path=ContractStart, StringFormat=dd/MM/yyyy, Mode=TwoWay}" Header="Contract Start" />
<DataGridTextColumn Binding="{Binding Path=ContractEnd, StringFormat=dd/MM/yyyy, Mode=TwoWay}" Header="Contract End" />
</DataGrid.Columns>
</DataGrid>
Contract.cs
public class Contract
{
public DateTime ContractStart { get; set; }
public DateTime ContractEnd { get; set; }
public Person Person { get; set; }
}
Person.cs
public class Person
{
public string LastName { get; set; }
public string GivenName { get; set; }
}
ViewModel.cs
public class ContractListViewModel : INotifyPropertyChanged
{
private ObservableCollection<Contract> _contractList;
public ObservableCollection<Contract> ContractList
{
get { return _contractList; }
set { SetField(ref _contractList, value, () => ContractList); } // Same as OnPropertyChanged
}
private Contract _selectedContract;
public Contract SelectedContract
{
get { return _selectedCrew; }
set { SetField(ref _selectedCrew, value, () => SelectedCrew); }
}
}
如果我将datagrid设置为readonly,它工作正常,问题是当我直接编辑LastName和GivenName DataGrid列时,它会崩溃,并抛出带有消息&#34的InvalidOperationException;双向绑定需要Path或XPath& #34 ;.但是如果我只是编辑ContractStart和ContractEnd就可以了。
我寻找了一些帮助,我想我和这个家伙遇到了同样的情况: DataGrid - "Two-way binding requires Path or XPath."
所以问题是Person属性为null,答案说我应该初始化DataContext中绑定的对象,但是没有说明如何做。
答案 0 :(得分:8)
实现Person属性的初始化,你可以修改如下
public class Contract
{
public Contract()
{
Person = new Person();
}
public string RankName { get; set; }
public string RankShortName { get; set; }
public Person Person { get; set; }
}
添加构造函数并相应地初始化