Question

我创建了一个UserControl，并且对控件中的几个自定义DependencyProperties有很多绑定。但出于某种原因，其中一个失败了，错误：

System.Windows.Data错误：4：找不到绑定源引用＆＃39; ElementName = YearSelectorControl＆＃39;。 BindingExpression：路径= SelectedBorderColor;的DataItem = NULL;目标元素是＆＃39; SolidColorBrush＆＃39; （的HashCode = 45568629）;目标属性是＆＃39;色＆＃39; （键入＆＃39;颜色＆＃39;）

该控件包含ToggleButton和Popup。单击Popup时打开ToggleButton时会出现错误。

这是xaml：

<UserControl x:Class="MyProject.Views.YearSelector"
             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:MyProject.Views"
             mc:Ignorable="d" 
             d:DesignHeight="23" d:DesignWidth="181"
             x:Name="YearSelectorControl">
    <UserControl.Resources>
        <SolidColorBrush x:Key="HoverColorBrush" Color="{Binding ElementName=YearSelectorControl, Path=HoverColor}"/> <!--This binding is virtually identical, but works fine-->
        <SolidColorBrush x:Key="SelectedBorderColorBrush" Color="{Binding ElementName=YearSelectorControl, Path=SelectedBorderColor}"/> <!--This is the binding that fails-->
        <local:YearToBackColorConverter x:Key="YearToBackColorConverter"/>
        <local:YearToBorderThicknessConverter x:Key="YearToBorderThicknessConverter"/>

        <Style x:Key="ForwardBackButtons" TargetType="{x:Type Button}" >
            <Setter Property="Background" Value="Transparent" />
            <Setter Property="BorderThickness" Value="0" />
            <Setter Property="FontFamily" Value="Arial" />
        </Style>
        <ControlTemplate x:Key="YearButton" TargetType="{x:Type Button}">
            <Grid Width="55" Height="30" Margin="2">
                <Rectangle x:Name="ButtonRectangle" Stroke="{StaticResource SelectedBorderColorBrush}"> <!--Use of the failing brush-->
                   <!--Removed code that determines StrokeThickness. Works correctly if Stroke set to a specific color rather than a Static Resource-->
                </Rectangle>
                <ContentPresenter VerticalAlignment="Center" HorizontalAlignment="Center"/>
            </Grid>
            <ControlTemplate.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter TargetName="ButtonRectangle" Property="Fill" Value="{StaticResource HoverColorBrush}"/> <!--Use of the properly binding brush-->
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </UserControl.Resources>

    <Grid>
        <!--Layout here-->
    </Grid>
</UserControl>

以下是绑定到DependencyProperties资源的两个SolidColorBrush的代码隐藏的摘录：

public Color HoverColor
{
    get { return (Color)GetValue(HoverColorProperty); }
    set { SetValue(HoverColorProperty, value); }
}
public static readonly DependencyProperty HoverColorProperty = 
    DependencyProperty.Register("HoverColor", typeof(Color), typeof(YearSelector), new PropertyMetadata(Color.FromArgb(255,190,230,253)));

public Color SelectedBorderColor
{
    get { return (Color)GetValue(SelectedBorderColorProperty); }
    set { SetValue(SelectedBorderColorProperty, value); }
}
public static readonly DependencyProperty SelectedBorderColorProperty = 
    DependencyProperty.Register("SelectedBorderColor", typeof(Color), typeof(YearSelector), new PropertyMetadata(Color.FromArgb(255,126,0,234)));

Answer 1

我离开了这几个月，专注于我的应用程序中更重要的元素，并最终回到它。我发现了解决方案，但我不确定为什么它首先是一个问题。

无论出于何种原因，将SolidColorBrush资源绑定到Stroke属性都不起作用。我所做的是将Color DependencyProperty直接绑定到Stroke并使用IValueConverter将其转换为SolidColorBrush。

XAML：

<Rectangle x:Name="ButtonRectangle" Stroke="{Binding ElementName=YearSelectorControl, Path=SelectedBorderColor, Converter={StaticResource ColorToSolidColorBrushConverter}}">

代码隐藏：

public class ColorToSolidColorBrushConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        try
        {
            Color c = (Color)value;
            return new SolidColorBrush(c);
        }
        catch
        {
            return new SolidColorBrush(Color.FromRgb(0,0,0));
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

在Stroke属性上使用SolidColorBrush资源时绑定失败

1 个答案: