我想在主细节关系中使用两个视图模型创建一个View。 （客户订单）
我想将一个主视图模型的SelectedCustomer绑定到详细视图模型的SelectedCustomer。我读到实现DependencyProperty可以完成这项工作，但是我没有更新属性，因为我在父视图中选择了不同的客户。我有什么想法吗？
谢谢
ViewModels的代码是：
namespace BindingViewModels.ViewModels
{
public class vmCustomers : INotifyPropertyChanged
{
protected ObservableCollection<Customer> _customers;
protected Customer _SelectedCustomer = null;
public event PropertyChangedEventHandler PropertyChanged;
public vmCustomers()
{
_customers = new ObservableCollection<Customer>();
_customers.Add( new Customer() { CustomerID = 1, CustName = "John Doe" });
_customers.Add(new Customer() { CustomerID = 2, CustName = "Johny Walker" });
_customers.Add(new Customer() { CustomerID = 3, CustName = "Joe Foreman" });
_customers.Add(new Customer() { CustomerID = 4, CustName = "Mike Tyson" });
_customers.Add(new Customer() { CustomerID = 5, CustName = "Salvatore Ferragamo" });
_customers.Add(new Customer() { CustomerID = 6, CustName = "Pato Donald" });
}
public ObservableCollection<Customer> Customers
{
get { return _customers; }
set { _customers = value; }
}
public Customer SelectedCustomer
{
get
{
return _SelectedCustomer;
}
set
{
_SelectedCustomer = value;
OnPropertyChanged("SelectedCustomer");
}
}
protected void OnPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(name));
}
}
public class vmOrders : DependencyObject
{
public static readonly DependencyProperty SelectedCustomerProperty =
DependencyProperty.Register("SelectedCustomer",
typeof(Customer),
typeof(vmOrders),
new PropertyMetadata(default(Customer), OnItemsPropertyChanged));
private static void OnItemsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
throw new NotImplementedException();
}
protected ObservableCollection<Order> _AllOrders;
protected ObservableCollection<Order> _CustomerOrders = null;
protected Customer _SelectedCustomer = null;
public vmOrders()
{
_AllOrders = new ObservableCollection<Order>();
_AllOrders.Add(new Order() { OrderID = 1, CustomerID = 1, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 100 });
_AllOrders.Add(new Order() { OrderID = 2, CustomerID = 1, Date = System.DateTime.Parse("2017-01-02"), TotalAmount = 200 });
_AllOrders.Add(new Order() { OrderID = 3, CustomerID = 1, Date = System.DateTime.Parse("2017-01-03"), TotalAmount = 300 });
_AllOrders.Add(new Order() { OrderID = 4, CustomerID = 1, Date = System.DateTime.Parse("2017-01-04"), TotalAmount = 400 });
_AllOrders.Add(new Order() { OrderID = 5, CustomerID = 2, Date = System.DateTime.Parse("2017-01-05"), TotalAmount = 500 });
_AllOrders.Add(new Order() { OrderID = 6, CustomerID = 2, Date = System.DateTime.Parse("2017-01-06"), TotalAmount = 600 });
_AllOrders.Add(new Order() { OrderID = 7, CustomerID = 3, Date = System.DateTime.Parse("2017-01-07"), TotalAmount = 700 });
_AllOrders.Add(new Order() { OrderID = 8, CustomerID = 3, Date = System.DateTime.Parse("2017-01-08"), TotalAmount = 800 });
_AllOrders.Add(new Order() { OrderID = 9, CustomerID = 3, Date = System.DateTime.Parse("2017-01-09"), TotalAmount = 900 });
_AllOrders.Add(new Order() { OrderID = 10, CustomerID = 3, Date = System.DateTime.Parse("2017-01-10"), TotalAmount = 1000 });
_AllOrders.Add(new Order() { OrderID = 11, CustomerID = 3, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1200 });
_AllOrders.Add(new Order() { OrderID = 12, CustomerID = 3, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1400 });
_AllOrders.Add(new Order() { OrderID = 13, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1200 });
_AllOrders.Add(new Order() { OrderID = 14, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5450 });
_AllOrders.Add(new Order() { OrderID = 15, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5020 });
_AllOrders.Add(new Order() { OrderID = 16, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5020 });
_AllOrders.Add(new Order() { OrderID = 17, CustomerID = 5, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5030 });
_AllOrders.Add(new Order() { OrderID = 18, CustomerID = 5, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5050 });
}
public ObservableCollection<Order> Orders
{
get {
if (SelectedCustomer != null)
return _CustomerOrders;
else
return _AllOrders;
}
set {
_AllOrders = value;
if (SelectedCustomer != null)
{
var linqresults = _AllOrders.Where(o => o.CustomerID == _SelectedCustomer.CustomerID);
_CustomerOrders = new ObservableCollection<Order>(linqresults);
}
else
{
_CustomerOrders = null;
}
}
}
public Customer SelectedCustomer
{
get
{
return (Customer)GetValue(SelectedCustomerProperty);
}
set
{
SetValue(SelectedCustomerProperty, value);
_SelectedCustomer = SelectedCustomer;
}
}
}
该视图的XAML是：
<Window x:Class="BindingViewModels.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:BindingViewModels"
xmlns:ViewModels="clr-namespace:BindingViewModels.ViewModels"
xmlns:Views="clr-namespace:BindingViewModels.Views"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<DataTemplate DataType="{x:Type ViewModels:vmCustomers}">
<Views:ViewCustomers/>
</DataTemplate>
<DataTemplate DataType="{x:Type ViewModels:vmOrders}">
<Views:ViewOrders/>
</DataTemplate>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="200"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ContentPresenter Grid.Row="0" Name="ContentCustomers" Content="{Binding ElementName=vmCustomersInstance}">
<ContentPresenter.DataContext>
<ViewModels:vmCustomers x:Name="vmCustomersInstance"/>
</ContentPresenter.DataContext>
</ContentPresenter>
<ContentPresenter Grid.Row="1" Name="ContentOrders" Content="{Binding ElementName= vmOrdersInstance}" MouseEnter="ContentOrders_MouseEnter">
<ContentPresenter.DataContext>
<ViewModels:vmOrders x:Name="vmOrdersInstance" SelectedCustomer="{Binding ElementName=vmCustomersInstance, Path=SelectedCustomer, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}" />
</ContentPresenter.DataContext>
</ContentPresenter>
</Grid>
</Window>
两个视图都是具有Grid和DataGrid的用户控件。
<UserControl x:Class="BindingViewModels.Views.ViewCustomers"
....
<Grid>
<DataGrid Name="DataGrid" ItemsSource="{Binding Path=Customers}" SelectedItem="{Binding Path=SelectedCustomer}" AutoGenerateColumns="True" ScrollViewer.VerticalScrollBarVisibility="Visible"/>
</Grid>
<UserControl x:Class="BindingViewModels.Views.ViewOrders"
....
<Grid>
<DataGrid Name="DataGrid" ItemsSource="{Binding Path=Orders}" AutoGenerateColumns="True" ScrollViewer.VerticalScrollBarVisibility="Visible"/>
</Grid>
经过多次尝试，我终于开始工作了。
综合观点：
<Window x:Class="BindingVM2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:BindingVM2"
xmlns:ViewModels="clr-namespace:BindingVM2.ViewModels"
xmlns:Views="clr-namespace:BindingVM2.Views"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<DataTemplate DataType="{x:Type ViewModels:vmCustomers}">
<Views:ViewCustomers/>
</DataTemplate>
<DataTemplate DataType="{x:Type ViewModels:vmOrders}">
<Views:ViewOrders/>
</DataTemplate>
<ViewModels:vmCustomers x:Key="vmCustomerInstance" />
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="200"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ContentPresenter Grid.Row="0" Name="ContentCustomers" Content="{StaticResource vmCustomerInstance}"/>
<ContentPresenter Grid.Row="1" Name="ContentOrders" Content="{Binding ElementName=vmOrdersInstance}">
<ContentPresenter.DataContext>
<ViewModels:vmOrders x:Name="vmOrdersInstance" SelectedCustomer="{Binding Source={StaticResource vmCustomerInstance}, Path=SelectedCustomer , Mode=TwoWay}" />
</ContentPresenter.DataContext>
</ContentPresenter>
</Grid>
</Window>
和ViewModels：
public class vmCustomers : DependencyObject, INotifyPropertyChanged
{
protected ObservableCollection<Customer> _customers;
public event PropertyChangedEventHandler PropertyChanged;
public static DependencyProperty SelectedCustomerProperty =
DependencyProperty.Register( "SelectedCustomer", typeof(Customer), typeof(vmCustomers),
new PropertyMetadata(default(Customer), new PropertyChangedCallback(OnSelectedCustomerChanged)));
private static void OnSelectedCustomerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Customer value = (Customer)e.NewValue;
vmCustomers vm = (vmCustomers)d;
vm.OnPropertyChanged("SelectedCustomer");
}
public Customer SelectedCustomer
{
get { return (Customer)GetValue(SelectedCustomerProperty); }
set { SetValue(SelectedCustomerProperty, value); }
}
public vmCustomers()
{
_customers = new ObservableCollection<Customer>();
_customers.Add( new Customer() { CustomerID = 1, CustName = "John Doe" });
_customers.Add(new Customer() { CustomerID = 2, CustName = "Johny Walker" });
_customers.Add(new Customer() { CustomerID = 3, CustName = "Joe Foreman" });
_customers.Add(new Customer() { CustomerID = 4, CustName = "Mike Tyson" });
_customers.Add(new Customer() { CustomerID = 5, CustName = "Salvatore Ferragamo" });
_customers.Add(new Customer() { CustomerID = 6, CustName = "Pato Donald" });
}
public ObservableCollection<Customer> Customers
{
get { return _customers; }
set { _customers = value; }
}
protected void OnPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(name));
}
}
public class vmOrders : DependencyObject ,INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected ObservableCollection<Order> _AllOrders;
protected ObservableCollection<Order> _CustomerOrders = null;
public static DependencyProperty SelectedCustomerProperty =
DependencyProperty.Register( "SelectedCustomer", typeof(Customer), typeof(vmOrders),
new FrameworkPropertyMetadata(default(Customer), new PropertyChangedCallback(OnSelectedCustomerPropertyChanged)));
private static void OnSelectedCustomerPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Customer value = (Customer)e.NewValue;
vmOrders vm = (vmOrders)d;
vm.ApplyFilter();
vm.OnPropertyChanged("Orders");
}
public Customer SelectedCustomer
{
get {return (Customer)GetValue(SelectedCustomerProperty); }
set { SetValue(SelectedCustomerProperty, value); }
}
public vmOrders()
{
_AllOrders = new ObservableCollection<Order>();
_AllOrders.Add(new Order() { OrderID = 1, CustomerID = 1, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 100 });
_AllOrders.Add(new Order() { OrderID = 2, CustomerID = 1, Date = System.DateTime.Parse("2017-01-02"), TotalAmount = 200 });
_AllOrders.Add(new Order() { OrderID = 3, CustomerID = 1, Date = System.DateTime.Parse("2017-01-03"), TotalAmount = 300 });
_AllOrders.Add(new Order() { OrderID = 4, CustomerID = 1, Date = System.DateTime.Parse("2017-01-04"), TotalAmount = 400 });
_AllOrders.Add(new Order() { OrderID = 5, CustomerID = 2, Date = System.DateTime.Parse("2017-01-05"), TotalAmount = 500 });
_AllOrders.Add(new Order() { OrderID = 6, CustomerID = 2, Date = System.DateTime.Parse("2017-01-06"), TotalAmount = 600 });
_AllOrders.Add(new Order() { OrderID = 7, CustomerID = 3, Date = System.DateTime.Parse("2017-01-07"), TotalAmount = 700 });
_AllOrders.Add(new Order() { OrderID = 8, CustomerID = 3, Date = System.DateTime.Parse("2017-01-08"), TotalAmount = 800 });
_AllOrders.Add(new Order() { OrderID = 9, CustomerID = 3, Date = System.DateTime.Parse("2017-01-09"), TotalAmount = 900 });
_AllOrders.Add(new Order() { OrderID = 10, CustomerID = 3, Date = System.DateTime.Parse("2017-01-10"), TotalAmount = 1000 });
_AllOrders.Add(new Order() { OrderID = 11, CustomerID = 3, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1200 });
_AllOrders.Add(new Order() { OrderID = 12, CustomerID = 3, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1400 });
_AllOrders.Add(new Order() { OrderID = 13, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 1200 });
_AllOrders.Add(new Order() { OrderID = 14, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5450 });
_AllOrders.Add(new Order() { OrderID = 15, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5020 });
_AllOrders.Add(new Order() { OrderID = 16, CustomerID = 4, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5020 });
_AllOrders.Add(new Order() { OrderID = 17, CustomerID = 5, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5030 });
_AllOrders.Add(new Order() { OrderID = 18, CustomerID = 5, Date = System.DateTime.Parse("2017-01-01"), TotalAmount = 5050 });
}
public void ApplyFilter()
{
if (SelectedCustomer != null)
{
var linqresults = _AllOrders.Where(o => o.CustomerID == SelectedCustomer.CustomerID);
_CustomerOrders = new ObservableCollection<Order>(linqresults);
}
else
{
_CustomerOrders = null;
}
}
public ObservableCollection<Order> Orders
{
get {
if (SelectedCustomer != null)
return _CustomerOrders;
else
return _AllOrders;
}
set {
_AllOrders = value;
OnPropertyChanged("Orders");
}
}
protected void OnPropertyChanged(string name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(name));
}
}
}