[英]Dependency Property ListBox's ItemsSource in UserControl
I develop new desktop app in C# WPF MVVM and I have a problem with data-binding. 我在C#WPF MVVM中开发了新的桌面应用程序,但是数据绑定存在问题。 I create my own UserControl 我创建自己的UserControl
<UserControl x:Class="Project.View.UserControls.BusListDeviceControl"
x:Name="BusList"
...
>
<Grid Grid.Column="0" Grid.Row="0" Margin="7, 5">
<Grid.RowDefinitions>
<RowDefinition Height="60"/>
<RowDefinition Height="*"/>
<RowDefinition Height="50"/>
</Grid.RowDefinitions>
<ListBox Grid.Row="1" ItemsSource="{Binding ElementName=BusList, Path=ItemsSource}" Background="{Binding ElementName=BusList, Path=BackgroundColor}" BorderBrush="{x:Null}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Margin="0,2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="25" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Image Grid.Column="0" Margin="5" Source="{Binding IconPath}"/>
<TextBlock Grid.Column="1" Text="{Binding Name}" FontFamily="Century Gothic" VerticalAlignment="Center" HorizontalAlignment="Left" FontSize="16"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</UserControl>
Code-behind 后台代码
public partial class BusListDeviceControl : UserControl, INotifyPropertyChanged
{
ObservableCollection<Device> devices;
string color;
public static readonly DependencyProperty DevicesProperty =
DependencyProperty.Register("Devices", typeof(ObservableCollection<Device>),
typeof(BusListDeviceControl), new PropertyMetadata (new ObservableCollection<Device>()));
public ObservableCollection<Device> Devices
{
get { return this.devices; }
set
{
this.devices = value;
RaisePropertyChanged("Devices");
}
}
public static readonly DependencyProperty BackgroundColorProperty =
DependencyProperty.Register("BackgroundColor", typeof(string), typeof(BusListDeviceControl));
public string BackgroundColor
{
get { return color; }
set
{
this.color = value;
RaisePropertyChanged("BackgroundColor");
}
}
public BusListDeviceControl()
{
InitializeComponent();
}
internal void RaisePropertyChanged(string prop)
{
if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(prop)); }
}
public event PropertyChangedEventHandler PropertyChanged;
}
And I want use this UserControl in my mainView. 我想在mainView中使用此UserControl。
<UserControl x:Class="Project.View.UserControls.IdentificationControl"
...>
<UserControl.DataContext>
<vm:IdentificationControlViewModel/>
</UserControl.DataContext>
<Grid Grid.Column="0" Margin="0">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="70" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<local:BusListDeviceControl Devices="{Binding Buses[0].Devices}" BackgroundColor="White" Grid.Column="0" Grid.Row="0" Margin="7, 5"></local:BusListDeviceControl>
</Grid>
</Grid>
</UserControl>
In IdentificationControlViewModel.cs I have public ObservableCollection Buses { get; 在IdentificationControlViewModel.cs中,我有公共的ObservableCollection总线。 set; 组; } and every Bus has public ObservableCollection Devices { get; },每辆公交车都有公共的ObservableCollection设备{ set; 组; }. }。 When I put all UserControl xaml code to mainView, binding work, but when I want use only to have clean code, binding for ItemsSource doesn't work but for BackgroundColor binding work properly. 当我将所有UserControl xaml代码放到mainView时,绑定工作正常,但是当我只想使用干净的代码时,ItemsSource的绑定不起作用,而BackgroundColor绑定则正常工作。
How to properly binding Buses[0].Devices to ItemsSource in my UserControl? 如何将Bus [0] .Devices正确绑定到UserControl中的ItemsSource?
The problem is that you are not using DependencyProperty
the right way. 问题是您没有以正确的方式使用DependencyProperty
。 see here for more information. 有关更多信息,请参见此处 。
Basically, when you use a DependencyProperty
then you do not use a field in the class, and the Properties should look like this: 基本上,当您使用DependencyProperty
那么你不使用类中的一个字段,属性应该是这样的:
public string BackgroundColor
{
get { return (string)GetValue(BackgroundColorProperty); }
set
{
SetValue(BackgroundColorProperty,value);
}
}
GetValue
and SetValue
are inherited from DependencyObject
. GetValue
和SetValue
从DependencyObject
继承。
also, when you use DependencyProperty
you do not need to implement INotifyPropertyChanged
另外,当您使用DependencyProperty
时,不需要实现INotifyPropertyChanged
your class shuld look like this: 您的课程应如下所示:
public partial class BusListDeviceControl : UserControl
{
public static readonly DependencyProperty DevicesProperty =
DependencyProperty.Register("Devices", typeof(ObservableCollection<Device>),
typeof(BusListDeviceControl), new PropertyMetadata (new ObservableCollection<Device>()));
public ObservableCollection<Device> Devices
{
get { return (ObservableCollection<Device>)GetValue(DevicesProperty ); }
set
{
SetValue(DevicesProperty ,value);
}
}
public static readonly DependencyProperty BackgroundColorProperty =
DependencyProperty.Register("BackgroundColor", typeof(string), typeof(BusListDeviceControl));
public string BackgroundColor
{
get { return (string)GetValue(BackgroundColorProperty); }
set
{
SetValue(BackgroundColorProperty,value);
}
}
public BusListDeviceControl()
{
InitializeComponent();
}
}
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