设置XAML属性在运行时会被覆盖吗？

当我使用以下行时，从Silverlight类库实现模板控件;设置XAML属性在运行时会被覆盖吗？

<labelSliderControl:SliderControl x:Name="sldX" Label="X" Value="4" />

我在VS Disign看查看滑块获得的4值但是，当我运行应用程序的滑块从0开始。所以，当我更改属性在XAML我可以看到的变化，但我也希望在课程的运行时间的值为4。在这种情况下，depency属性是否覆盖了值？

这是Silverlight类库中的模板控件;

<Style TargetType="local:SliderControl"> 
    <Setter Property="Template"> 
     <Setter.Value> 
      <ControlTemplate TargetType="local:SliderControl"> 
       <Grid x:Name="LayoutRoot" Background="White"> 
        <Grid.RowDefinitions> 
         <RowDefinition Height="Auto" /> 
         <RowDefinition /> 
         <RowDefinition Height="Auto" /> 
        </Grid.RowDefinitions> 
        <sdk:Label x:Name="lblLabel" Content="" HorizontalContentAlignment="Center" /> 
        <Slider x:Name="sldValue" Grid.Row="1" Orientation="Vertical" /> 
        <TextBox x:Name="txtValue" Grid.Row="2" MaxWidth="50" MinWidth="50" Text="{Binding ElementName=sldValue, Path=Value, StringFormat=\{0:N2\}}" /> 
       </Grid> 
      </ControlTemplate> 
     </Setter.Value> 
    </Setter> 
</Style> 

[TemplatePart(Name = "sldValue", Type = typeof(Slider)), TemplatePart(Name = "lblLabel", Type = typeof(Label))] 
public class SliderControl : Control 
{ 
    private Slider _sliderElement; 

    private Slider SliderElement 
    { 
     get { return _sliderElement; } 
     set { 
      if (_sliderElement != null) 
       _sliderElement.ValueChanged -= new RoutedPropertyChangedEventHandler<double>(sldValue_ValueChanged);; 

      _sliderElement = value; 

      if (_sliderElement != null) 
       _sliderElement.ValueChanged += new RoutedPropertyChangedEventHandler<double>(sldValue_ValueChanged); 
     } 
    } 

    public event EventHandler<ValueChangingEventArgs> ValueChanging; 

    public static readonly DependencyProperty ValueProperty = 
     DependencyProperty.Register("Value", typeof(double), typeof(SliderControl), new PropertyMetadata(0.0, ValuePropertyChanged)); 

    private static void ValuePropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args) 
    { 
     if (obj is SliderControl) 
     { 
      SliderControl sliderUserControl = (SliderControl)obj; 
      if (sliderUserControl.SliderElement != null) 
      { 
       sliderUserControl.SliderElement.Value = (double)args.NewValue; 
      } 
     } 
    } 

    public SliderControl() 
    { 
     this.DefaultStyleKey = typeof(SliderControl); 
    } 

    private void sldValue_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e) 
    { 
     if (ValueChanging != null) 
     { 
      ValueChanging(this, new ValueChangingEventArgs(e.OldValue, e.NewValue)); 
     } 
    } 

    public override void OnApplyTemplate() 
    { 
     SliderElement = GetTemplateChild("sldValue") as Slider; 
     base.OnApplyTemplate(); 
    } 
}

来源

2010-09-24 Magiel

我在注册DependencyProperty时看不到“Value”属性。

public double Value 
{ 
    get { return (double)base.GetValue(ValueProperty); } 
    set { base.SetValue(ValueProperty, value); } 
}

，然后将属性绑定到控制在构造函数中：

public SliderControl(){ 

    InitializeComponent(); 

    this.sldValue.SetBinding(Slider.ValueProperty, new Binding() 
    { 
     Source = this, 
     Path = new PropertyPath("Value"), 
     Mode = BindingMode.TwoWay 
    }); 
}

来源

2010-09-24 21:36:48 Gabe

感谢您的快速回复。 – Magiel 2010-09-24 22:42:42

感谢您的快速回复。注册DependencyProperty时声明的“Value”属性被错误地发布。我很抱歉。我尝试了你有趣的解决方案，但我正在尝试使用模板控件。我假设因为OnApplyTemplate 尚未被调用，我没有在我的模板控件中将Slider作为Child控件的引用集。使用附加属性是否是一个想法，或者我正在考虑从silder继承整个模板化控件并传递所有属性。我认为必须有更好的解决方案。 – Magiel 2010-09-24 22:54:57

我得到它的工作！我只是把gmcalab的解决方案放在OnApplyTemplate中。感谢gmcalab。

public override void OnApplyTemplate() 
    { 
     SliderElement = GetTemplateChild("sldValue") as Slider; 
     if (SliderElement != null) 
     { 
      SliderElement.SetBinding(Slider.ValueProperty, new Binding() 
      { 
       Source = this, 
       Path = new PropertyPath("Value"), 
       Mode = BindingMode.TwoWay 
      }); 
     } 
     base.OnApplyTemplate(); 
    }

来源

2010-09-24 23:04:12 Magiel

设置XAML属性在运行时会被覆盖吗？

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