Question

在下面的XAML UserControl中，我将一些项绑定到UserControl的链接类中的属性。

<UserControl x:Class="Kiosk.EventSelectButton"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:Kiosk"
    Height="130" Width="130">
    <Grid>
        <Button 
            Style="{DynamicResource DarkButton130x130}" 
            HorizontalAlignment="Left" 
            VerticalAlignment="Center">
            <Grid Margin="0,0,0,0" Height="118" Width="118">
                <Image VerticalAlignment="Top" HorizontalAlignment="Center" Source="image/select_button_arrows.png" />
                <Image x:Name="EventImageComponent" VerticalAlignment="Center" HorizontalAlignment="Center" Effect="{DynamicResource KioskStandardDropShadow}" Source="{Binding Path=EventImage}" />
                <TextBlock x:Name="SelectTextBlock" Text="{Binding Path=SelectText}" VerticalAlignment="Top" HorizontalAlignment="Center" Margin="0,-2,0,0" FontSize="10pt" Foreground="#5aaff5" />
                <TextBlock x:Name="LabelTextBlock" VerticalAlignment="Bottom" HorizontalAlignment="Right" Margin="0,0,0,0" FontSize="14pt" FontWeight="Bold" Text="{Binding Path=Label}"/>
            </Grid>
        </Button>
    </Grid>
</UserControl>

在链接类'contstructor中，我将项目的DataContext应用于 this ，如下所示。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Kiosk
{
    /// <summary>
    /// Interaction logic for EventSelectButton.xaml
    /// </summary>
    public partial class EventSelectButton : UserControl
    {

        public String ValueContainer;

        private String _EventImage;

        public String EventImage
        {
            get
            {
                return _EventImage;
            }
            set
            {
                _EventImage = value;
            }
        }

        private String _Label;

        public String Label
        {
            get
            {
                return _Label;
            }
            set
            {
                _Label = value;
            }
        }

        private String _SelectText;

        public String SelectText 
        {
            get 
            { 
                return _SelectText; 
            }
            set 
            { 
                _SelectText = value; 
            }
        }

        public EventSelectButton()
        {
            InitializeComponent();
            LabelTextBlock.DataContext = this;
            SelectTextBlock.DataContext = this;
            EventImageComponent.DataContext = this;
        }
    }
}

修改

虽然这是按预期工作的，但我很想知道是否有更简单的方法可以做到这一点。（编辑，经验教训。）这实际上不会超出初始化，公共属性将被设置，但是因为类不使用DependentProperties或者实现INotifyPropertyChanged，绑定将不起作用正如所料。（结束编辑）

例如，

我可以将XAML中这些项的DataContext设置为 this （作为EventSelectButton实例），如果是，如何？
或者，是否可以从UserControl父级继承DataContext，从而使绑定路径更简单。

到目前为止，我发现的唯一替代品更加冗长，例如：使用RelativeSource绑定方法来定位EventSelectButton Ancestor。

所以，请让我知道我可以改进这种绑定表达式的任何方法，并且非常感谢任何关于在UserComponent中绑定的最佳实践的评论。

Answer 1

一种方法是执行以下操作：

在XAML中命名您的UserControl。
将根元素（即网格）的DataContext绑定到UserControl。

像这样：

<UserControl x:Name="uc">
  <Grid DataContext="{Binding ElementName=uc}">
  .
  .
  .
  </Grid>
</UserControl>

现在，你会问，为什么不设置UserControl本身的DataContext？好吧，这只是确保设置UserControl实例的DataContext仍然可以工作，而不会影响UserControl的可视树中的绑定。所以像下面这样的东西仍然可以正常工作。

<Window>
  <uc:EventSelectButton DataContext="{Binding SomeDataContext}" Width="{Binding SomeDataContextWidth}"/>
</Window>

修改

要使解决方案完整，需要将UserControl中的属性更改为使用DependencyProperty对象。以下是代码的更新：

XAML：

<UserControl x:Class="Kiosk.EventSelectButton" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:Kiosk" x:Name="root" Height="130" Width="130"> <Grid x:Name="LayoutRoot" DataContext="{Binding ElementName=root}"> <Button Style="{DynamicResource DarkButton130x130}" HorizontalAlignment="Left" VerticalAlignment="Center"> <Grid Margin="0,0,0,0" Height="118" Width="118" > <Image VerticalAlignment="Top" HorizontalAlignment="Center" Source="image/select_button_arrows.png" /> <Image Source="{Binding EventImage}" VerticalAlignment="Center" HorizontalAlignment="Center" Effect="{DynamicResource KioskStandardDropShadow}" /> <TextBlock Text="{Binding SelectText}" VerticalAlignment="Top" HorizontalAlignment="Center" Margin="0,-2,0,0" FontSize="10pt" Foreground="#5aaff5" /> <TextBlock Text="{Binding Label}" VerticalAlignment="Bottom" HorizontalAlignment="Right" Margin="0,0,0,0" FontSize="14pt" FontWeight="Bold" /> </Grid> </Button> </Grid> </UserControl>

代码隐藏：

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace Kiosk { public partial class EventSelectButton : UserControl { public static readonly DependencyProperty EventImageProperty = DependencyProperty.Register( "EventImage", typeof(string), typeof(EventSelectButton)); public String EventImage { get { return (string)GetValue(EventImageProperty); } set { SetValue(EventImageProperty, value); } } public static readonly DependencyProperty SelectTextProperty = DependencyProperty.Register( "SelectText", typeof(string), typeof(EventSelectButton)); public String SelectText { get { return (string)GetValue(SelectTextProperty); } set { SetValue(SelectTextProperty, value); } } public static readonly DependencyProperty LabelProperty = DependencyProperty.Register( "Label", typeof(string), typeof(EventSelectButton)); public String Label { get { return (string)GetValue(LabelProperty); } set { SetValue(LabelProperty, value); } } public EventSelectButton() { InitializeComponent(); } } }

WPF DataContext ...寻找最简单的语法

修改

1 个答案: