我有一个窗口和一个用户控件在这个窗口中使用。
我已经做到了以下几点:
- 将窗口属性
- 绑定到窗口的视图模型属性。 将用户控件属性
- 绑定到用户控件的视图模型属性。
- 将用户控件的属性绑定到窗口的视图模型属性。
在我看来,我认为如果我按特定值设置窗口属性,则用户控件的视图模型的属性将设置为相同的值。
但是用户控件的视图模型的属性未设置为相同的值。
这是整个代码。
MainWindow.xaml.cs
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
Window1 w = new Window1();
w.Mode = RegisterMode.Update;
w.Show();
}
}
窗口1.xaml
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MVVMTest2" x:Name="window" x:Class="MVVMTest2.Window1"
Title="Window1" Height="300" Width="300">
<Window.DataContext>
<local:WindowViewModel></local:WindowViewModel>
</Window.DataContext>
<Grid>
<local:UserControl1 x:Name="uc1" HorizontalAlignment="Left" Height="100" Margin="77,116,0,0" VerticalAlignment="Top" Width="100" Mode="{Binding DataContext.Mode, ElementName=window, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
<Button Content="Button" HorizontalAlignment="Left" Margin="156,43,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
</Grid>
</Window>
窗口1.xaml.cs
public partial class Window1 : Window
{
public RegisterMode Mode
{
get { return (RegisterMode)GetValue(ModeProperty); }
set { SetValue(ModeProperty, value); }
}
// Using a DependencyProperty as the backing store for Mode. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ModeProperty =
DependencyProperty.Register("Mode", typeof(RegisterMode), typeof(Window1), new PropertyMetadata(RegisterMode.None));
public Window1()
{
InitializeComponent();
Binding modeBinding = new Binding();
modeBinding.Source = this.DataContext;
modeBinding.Path = new PropertyPath("Mode");
modeBinding.Mode = BindingMode.TwoWay;
modeBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
this.SetBinding(Window1.ModeProperty, modeBinding);
}
private void Button_Click(object sender, RoutedEventArgs e)
{
MessageBox.Show((uc1.DataContext as UCViewModel).Mode.ToString());
}
}
窗口视图模型.cs
public class WindowViewModel : INotifyPropertyChanged
{
RegisterMode mode = RegisterMode.None;
public event PropertyChangedEventHandler PropertyChanged;
public RegisterMode Mode
{
get { return this.mode; }
set
{
this.mode = value;
RaisePropertyChanged("Mode");
}
}
void RaisePropertyChanged(string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
用户控制1.xaml
<UserControl x:Class="MVVMTest2.UserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MVVMTest2"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.DataContext>
<local:UCViewModel></local:UCViewModel>
</UserControl.DataContext>
<Grid>
</Grid>
</UserControl>
用户控制1.xaml.cs
public partial class UserControl1 : UserControl
{
public RegisterMode Mode
{
get { return (RegisterMode)GetValue(ModeProperty); }
set { SetValue(ModeProperty, value); }
}
// Using a DependencyProperty as the backing store for Mode. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ModeProperty =
DependencyProperty.Register("Mode", typeof(RegisterMode), typeof(UserControl1), new PropertyMetadata(RegisterMode.None));
public UserControl1()
{
InitializeComponent();
Binding modeBinding = new Binding();
modeBinding.Source = this.DataContext;
modeBinding.Path = new PropertyPath("Mode");
modeBinding.Mode = BindingMode.TwoWay;
modeBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
this.SetBinding(UserControl1.ModeProperty, modeBinding);
}
}
UCViewModel.cs
public class UCViewModel : INotifyPropertyChanged
{
RegisterMode mode = RegisterMode.None;
public event PropertyChangedEventHandler PropertyChanged;
public RegisterMode Mode
{
get { return this.mode; }
set
{
this.mode = value;
RaisePropertyChanged("Mode");
}
}
void RaisePropertyChanged(string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
我做错了什么?请让我知道。
尝试使用此解决方案,在ViewModels
之间使用组合。
窗口1.xaml
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:MVVMTest2" x:Name="window" x:Class="MVVMTest2.Window1"
Title="Window1" Height="300" Width="300"
Mode={Binding UcViewModel.Mode}> <!-- Added this binding -->
<!-- MOVED THIS TO THE CODE-BEHIND
<Window.DataContext>
<local:WindowViewModel></local:WindowViewModel>
</Window.DataContext>
-->
<Grid>
<local:UserControl1 x:Name="uc1" HorizontalAlignment="Left" Height="100" Margin="77,116,0,0" VerticalAlignment="Top" Width="100"
Mode="{Binding UcViewModel.Mode}"/>
<Button Content="Button" HorizontalAlignment="Left" Margin="156,43,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click"/>
</Grid>
</Window>
窗口1.xaml.cs
public partial class Window1 : Window
{
public RegisterMode Mode
{
get { return (RegisterMode)GetValue(ModeProperty); }
set { SetValue(ModeProperty, value); }
}
// Using a DependencyProperty as the backing store for Mode. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ModeProperty =
DependencyProperty.Register("Mode", typeof(RegisterMode), typeof(Window1), new PropertyMetadata(RegisterMode.None));
public Window1()
{
InitializeComponent();
/* THIS IS NOT NEEDED
Binding modeBinding = new Binding();
modeBinding.Source = this.DataContext;
modeBinding.Path = new PropertyPath("Mode");
modeBinding.Mode = BindingMode.TwoWay;
modeBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
this.SetBinding(Window1.ModeProperty, modeBinding)
*/
// Use the following instead:
this.DataContext = new WindowViewModel();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
MessageBox.Show((uc1.DataContext as UCViewModel).Mode.ToString());
}
}
用户控制1.xaml
<UserControl x:Class="MVVMTest2.UserControl1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MVVMTest2"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<!-- THIS PART IS NOT NEEDED
<UserControl.DataContext>
<local:UCViewModel></local:UCViewModel>
</UserControl.DataContext>
-->
<Grid>
</Grid>
</UserControl>
用户控制1.xaml.cs
public partial class UserControl1 : UserControl
{
public RegisterMode Mode
{
get { return (RegisterMode)GetValue(ModeProperty); }
set { SetValue(ModeProperty, value); }
}
// Using a DependencyProperty as the backing store for Mode. This enables animation, styling, binding, etc...
public static readonly DependencyProperty ModeProperty =
DependencyProperty.Register("Mode", typeof(RegisterMode), typeof(UserControl1), new PropertyMetadata(RegisterMode.None));
public UserControl1()
{
InitializeComponent();
/* THIS IS NOT NEEDED
Binding modeBinding = new Binding();
modeBinding.Source = this.DataContext;
modeBinding.Path = new PropertyPath("Mode");
modeBinding.Mode = BindingMode.TwoWay;
modeBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
this.SetBinding(UserControl1.ModeProperty, modeBinding);
*/
}
}
窗口视图模型.cs
public class WindowViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
/* Remove this:
RegisterMode mode = RegisterMode.None;
public RegisterMode Mode
{
get { return this.mode; }
set
{
this.mode = value;
RaisePropertyChanged("Mode");
}
}
*/
// Use composition instead
UCViewModel _ucViewModel = null;
public UCViewModel UcViewModel
{
get
{
if (_ucViewModel == null)
{
_ucViewModel = new UCViewModel();
}
return _ucViewModel;
}
}
void RaisePropertyChanged(string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
还有一件事,您可能希望将 ViewModel Mode
属性重命名为另一个名称,如 RegMode
。原因是它在绑定期间在 XAML 代码中令人困惑。
由此: {Binding Mode, Mode=TwoWay}
或者,这个: {Binding Path=Mode, Mode=TwoWay}
对于这个不太令人困惑的问题: {Binding RegMode, Mode=TwoWay}