我编写了带有2个按钮和一个复选框的用户控件，现在我想将Commands绑定到数据上下文-每个按钮和复选框。但是我不知道如何定义命令绑定。我想我需要在用户控件中使用某种ICommand属性-但是如何连接用户的数据上下文命令委托？我想使用用户控件来管理集合中的每个项目，如下所示：
<ItemsControl ItemsSource="{Binding Path=MoneyInfo}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<local:ChannelSetupControl
CurrentCount="{Binding Count}"
CoinValue="{Binding Value}"
UpCommand="{Binding DataContextUp}"
DownCommand="{Binding DataContextDown}"
ChangeCheckboxCommand="{Binding DataContextChange}"></local:ChannelSetupControl>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
XAML用户控件
<UserControl>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="3*"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"></ColumnDefinition>
<ColumnDefinition Width="*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="0" Text="{Binding CoinValue}" TextAlignment="Center"></TextBlock>
<TextBlock Grid.Column="0" Grid.Row="1" Text="{Binding CurrentCount, Mode=TwoWay}" TextAlignment="Center" VerticalAlignment="Center" FontSize="30"></TextBlock>
<StackPanel Grid.Column="1" Grid.Row="1" VerticalAlignment="Center">
<Button Content="+ 10" Padding="0 5"></Button>
<Button Content="- 10" Padding="0 5"></Button>
</StackPanel>
<CheckBox Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="2" IsChecked="{Binding Cycling, Mode=TwoWay}" Content="recycling" VerticalContentAlignment="Center"></CheckBox>
</Grid>
</UserControl>
和后面的代码，这就是我迷路的地方-如何定义UpCommand，DownCommand和ChangeCheckboxCommand？
public partial class ChannelSetupControl : UserControl, INotifyPropertyChanged
{
private int currentCount;
private bool cycling;
private double coinValue;
public int Step { get; set; }
public double CoinValue { get { return coinValue; } set { coinValue = value; NotifyPropertyChanged("CoinValue"); } }
public int CurrentCount { get { return currentCount; } set { currentCount = value; NotifyPropertyChanged("CurrentCount"); } }
public bool Cycling { get { return cycling; } set { cycling = value; NotifyPropertyChanged("Cycling"); } }
public ChannelSetupControl()
{
InitializeComponent();
DataContext = this;
CurrentCount = 0;
Step = 10;
Cycling = false;
CoinValue = 0;
}
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
首先，您的ChannelSetupControl类extends UserControl，因此它隐式地扩展了DependencyObjectclass。这意味着您可以使用“依赖项属性”代替实现INotifyPropertyChanged。
因此，您可以在ChannelSetupControl类中定义一个依赖项属性，如下所示：
public static readonly DependencyProperty UpCommandProperty =
DependencyProperty.Register("UpCommand", typeof(ICommand), typeof(ChannelSetupControl));
public ICommand UpCommand
{
get { return (ICommand)GetValue(UpCommandProperty); }
set { SetValue(UpCommandProperty, value); }
}
同时在您的控件XAML中：
<Button Command="{Binding RelativeSource={RelativeSource Mode=Self}, Path=UpCommand, Mode=OneWay}"
Content="+ 10" Padding="0 5" />
通过这种方式，您可以在窗口XAML中编写：
<local:ChannelSetupControl UpCommand="{Binding UpCommand, Mode=OneWay}" ... />
您可以对其他控件使用相同的“模式”。关于ICommand，有很多实现。我更喜欢的是所谓的委托命令（有关示例，您可以在此处查看）。我希望这个快速的解释可以对您有所帮助。
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我来说两句