鏈接依賴屬性xaml wpf

我有一個用戶控件，我希望通過它的父級xaml（本例中是一個wpf頁面）進行訪問。我的用戶控件有一個標籤屬性，我希望通過將頁面xaml綁定到傳遞到頁面xaml的datacontext來設置它。鏈接依賴屬性xaml wpf

在下面的示例中，xaml頁面中的數據綁定似乎正常工作。我可以通過頁面xaml設置用戶控件標籤的內容，只要我不嘗試將其綁定到頁面datacontext，當我嘗試這樣做時，標籤始終顯示爲空白。

我遵循了本網站上提出的其他一些相關示例，但到目前爲止還沒有找到我要出錯的地方。任何建議將不勝感激。

用戶控件XAML

<UserControl x:Class="Pipeline_General.Custom_Controls.AttributeStack" 
     xmlns:pm="clr-namespace:Pipeline_General" 
     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" 
     mc:Ignorable="d" 
     DataContext = "{Binding RelativeSource={RelativeSource Self}}" 
     d:DesignHeight="30" d:DesignWidth="300"> 
<Grid> 
    <Grid.ColumnDefinitions> 
     <ColumnDefinition Width="2*" /> 
     <ColumnDefinition Width="3*" /> 
    </Grid.ColumnDefinitions> 
    <Label Foreground="{x:Static pm:myBrushes.pink}" Content="{Binding Path=Attr}" Grid.Column="0" HorizontalAlignment="Right" FontFamily="Calibri" FontSize="14" Margin="5,0,5,0"/> 
    <Label x:Name="ValLabel" Foreground="{x:Static pm:myBrushes.blue}" Grid.Column="1" HorizontalAlignment="Left" FontFamily="Calibri" FontSize="14" Margin="5,0,5,0"/> 
</Grid>

用戶控件代碼背後

public partial class AttributeStack : UserControl 
{ 


    public static readonly DependencyProperty AttrProperty = DependencyProperty.Register 
     (
      "Attr", 
      typeof(string), 
      typeof(AttributeStack), 
      new PropertyMetadata(string.Empty) 
     ); 

    public static readonly DependencyProperty ValProperty = DependencyProperty.Register 
      (
       "Val", 
       typeof(string), 
       typeof(AttributeStack), 
       new PropertyMetadata(string.Empty) 
      ); 

    public static readonly DependencyProperty ValTextProperty = DependencyProperty.Register 
     (
       "ValText", 
       typeof(string), 
       typeof(AttributeStack), 
       new PropertyMetadata(string.Empty) 
     ); 

    public string Val 
    { 
     get { return (string)GetValue(ValProperty); } 
     set { SetValue(ValProperty, value); } 
    } 

    public string ValText 
    { 
     get { return (string)GetValue(ValTextProperty); } 
     set { SetValue(ValTextProperty, value); } 
    } 


    public string Attr 
    { 
     get { return (string)GetValue(AttrProperty); } 
     set { SetValue(AttrProperty, value); } 
    } 


    public AttributeStack() 
    { 
     InitializeComponent(); 

     Binding valBinding = new Binding("Val") 
     { 
      Source = Val, 
      Mode = BindingMode.OneWay 
     }; 

     Binding textBinding = new Binding("Content") 
     { 
      Source = this.ValLabel.Content, 
      Mode = BindingMode.OneWay 
     }; 

     ValLabel.SetBinding(Label.ContentProperty, valBinding); 
     this.SetBinding(AttributeStack.ValTextProperty, textBinding); 
    } 
}

頁XAML

<Page x:Class="Pipeline_General.SceneView" x:Name="page" 
    xmlns:pm="clr-namespace:Pipeline_General" 
    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" 
    mc:Ignorable="d" 
    xmlns:cc="clr-namespace:Pipeline_General.Custom_Controls" 
    d:DesignHeight="800" d:DesignWidth="600" 
    DataContext = "{Binding RelativeSource={RelativeSource Self}}" 
    Title="SceneView"> 
<Grid> 
    <ScrollViewer> 
     <Grid> 
      <Grid.ColumnDefinitions> 
       <ColumnDefinition Width="*" /> 
       <ColumnDefinition Width="*" /> 
      </Grid.ColumnDefinitions> 
      <StackPanel Grid.Column="0"> 
       <Expander IsExpanded="True" Margin="5"> 
        <Expander.Header> 
         <Grid x:Name="Grid" HorizontalAlignment="Stretch" Width="NaN"> 
          <Border x:Name="Border" Background="Transparent" HorizontalAlignment="Stretch" BorderBrush="{x:Static pm:myBrushes.blue}" BorderThickness="0,0,0,1" 
         Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Expander}}, Path=ActualWidth}"> 
           <TextBlock x:Name="HeaderText" FontSize ="18" FontFamily="Calibri" Foreground="{x:Static pm:myBrushes.blue}" Text="General Info: " /> 
          </Border> 
         </Grid> 
        </Expander.Header> 
        <StackPanel> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Title:" Val="{Binding Path=DataContext.Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Episode:" Val="{Binding Path=DataContext.episode.Key, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Sequence:" Val="{Binding Path=DataContext.sequence.Key, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Scene:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Assigned:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Status:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Last Saved (Time):" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Last Saved (User):" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Due:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
        </StackPanel> 
       </Expander> 
      </StackPanel> 

      <StackPanel Grid.Column="1"> 
       <cc:Playblast_Viewer x:Name="PlayblastView"/> 
       <cc:FeedbackCtrl Header="Feedback:"/> 
       <cc:FeedbackCtrl Header="NoticeBoard:"/> 
      </StackPanel> 

     </Grid> 
    </ScrollViewer> 
</Grid>

標籤結合DataContext.Title字段似乎是工作，並設置ATTR字段似乎正確工作/作爲也在意料之中。因此，它只是Val域，我不能工作..

已更新，其中包括頁面代碼後面。儘管這裏幾乎沒有任何事情發生。

public partial class SceneView : Page 
{ 
    public Scene scene { get; set; } 
    public SceneView(Scene s) 
    { 
     InitializeComponent(); 
     scene = s; 
     this.DataContext = scene; 
    } 
}

我明白，即時通訊的IM非常漂亮，所以我很有可能嘗試做更好的完全不同的方式。在這種情況下，場景對象具有多個使用頁面和用戶控件進行公開的字段。我編寫了完整的應用程序在沒有任何xaml的代碼背後，但現在我正在嘗試自學xaml並讓原型的下一個版本更加流暢，並將所需編碼減少了80％。

場景對象，它是頁面對象的數據上下文，我試圖發送字段到用戶控件，即。 page.DataContext.episode.Key是代碼後面的合法字段。通過上面的xaml我正在尋找它的值發送到Val字段，然後Val字段將更新ValText（用戶控件中的標籤）內容屬性。

來源

2014-08-30 xxdefaultxx

鏈/佈線是從不與依賴屬性的問題。對我來說，你的邏輯似乎有點糾結。我發現有點難以想象所需。如果你能爲相同的東西畫出一些東西，我會很感激。即。財產來源，調解人和目標。 – pushpraj 2014-08-30 05:45:30

你能分享頁面背後的代碼嗎？ – 2014-08-30 06:05:36

請看這裏http://stackoverflow.com/questions/23482734/wpf-chain-binding?rq=1 – Developer 2014-08-30 06:46:00

我找到了問題/問題。他們中的大多數人，因爲我仍然是一個新手在XAML。

我意識到datacontext不訪問字段，如果他們沒有與get/set訪問器聲明。我在後面的頁面代碼中更改了場景聲明，以便它成爲依賴項對象而不是鏈接綁定我使用依賴項屬性更改事件來設置usercontrols標籤內容。

public partial class AttributeStack : UserControl 
{ 
    #region Val (DependencyProperty) 
    public string Val 
    { 
     get { return (string)GetValue(ValProperty); } 
     set { SetValue(ValProperty, value); } 
    } 
    public static readonly DependencyProperty ValProperty = 
     DependencyProperty.Register("Val", typeof(string), typeof(AttributeStack), 
      new PropertyMetadata { PropertyChangedCallback = ValChanged }); 
    private static void ValChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
    { 
     AttributeStack aStack = d as AttributeStack; 
     if (aStack != null && e.NewValue != null) 
     { 
      aStack.ValLabel.Content = e.NewValue.ToString(); 
     } 
    } 
    #endregion 

    public static readonly DependencyProperty AttrProperty = DependencyProperty.Register 
     (
      "Attr", 
      typeof(string), 
      typeof(AttributeStack), 
      new PropertyMetadata(string.Empty) 
     ); 

    public string Attr 
    { 
     get { return (string)GetValue(AttrProperty); } 
     set { SetValue(AttrProperty, value); } 
    } 

    public AttributeStack() 
    { 
     InitializeComponent(); 
    } 
}

}

public partial class SceneView : Page 
{ 
    public static readonly DependencyProperty sceneProperty = DependencyProperty.Register 
     (
      "scene", 
      typeof(Scene), 
      typeof(SceneView) 
     ); 

    public Scene scene 
    { 
     get { return (Scene)GetValue(sceneProperty); } 
     set { SetValue(sceneProperty, value); } 
    } 
    public SceneView(Scene s) 
    { 
     InitializeComponent(); 
     scene = s; 

     this.DataContext = scene; 
    } 
} 

<Page x:Class="Pipeline_General.SceneView" x:Name="page" 
    xmlns:pm="clr-namespace:Pipeline_General" 
    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" 
    mc:Ignorable="d" 
    xmlns:cc="clr-namespace:Pipeline_General.Custom_Controls" 
    d:DesignHeight="800" d:DesignWidth="600" 
    DataContext = "{Binding RelativeSource={RelativeSource Self}}" 
    Title="SceneView"> 
<Grid> 
    <ScrollViewer> 
     <Grid> 
      <Grid.ColumnDefinitions> 
       <ColumnDefinition Width="*" /> 
       <ColumnDefinition Width="*" /> 
      </Grid.ColumnDefinitions> 
      <StackPanel Grid.Column="0"> 
       <Expander IsExpanded="True" Margin="5"> 
        <Expander.Header> 
         <Grid x:Name="Grid" HorizontalAlignment="Stretch" Width="NaN"> 
          <Border x:Name="Border" Background="Transparent" HorizontalAlignment="Stretch" BorderBrush="{x:Static pm:myBrushes.blue}" BorderThickness="0,0,0,1" 
         Width="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Expander}}, Path=ActualWidth}"> 
           <TextBlock x:Name="HeaderText" FontSize ="18" FontFamily="Calibri" Foreground="{x:Static pm:myBrushes.blue}" Text="General Info: " /> 
          </Border> 
         </Grid> 
        </Expander.Header> 
        <StackPanel> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Title:" Val="{Binding Path=scene.Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Episode:" Val="{Binding Path=scene.episode.Key, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Sequence:" Val="{Binding Path=scene.sequence.Key, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Scene:" Val="{Binding Path=scene.Key, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Assigned:" Val="{}"/> 

         <cc:AttributeStack Attr="Status:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Last Saved (Time):" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <cc:AttributeStack Attr="Last Saved (User):" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
         <Separator Foreground="Transparent" Height="0" Margin="5"/> 
         <cc:AttributeStack Attr="Due:" Val="{Binding Path=Title, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"/> 
        </StackPanel> 
       </Expander> 
      </StackPanel> 

      <StackPanel Grid.Column="1"> 
       <cc:Playblast_Viewer x:Name="PlayblastView"/> 
       <cc:FeedbackCtrl Header="Feedback"/> 
       <cc:FeedbackCtrl Header="NoticeBoard"/> 
      </StackPanel> 

     </Grid> 
    </ScrollViewer> 
</Grid>

來源

2014-08-30 09:27:45 xxdefaultxx

鏈接依賴屬性xaml wpf

回答

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