Bindinq XAML elemenst在stackpanel中对象（不是集合） [英] Bindinq XAML elemenst in stackpanel to an object (not a collection)

问题描述

我有以下课程

ProviderDataItem

SiteDataItem

然后我使用它们在我的SampleSiteDataSource中创建一个网站类

Then I use both to create a Sites class in my SampleSiteDataSource

public class Sites
{
   private ProviderDataItem _provider = new ProviderDataItem();
   public ProviderDataItem Provider
   {
       get { return this._provider; }
   }
private ObservableCollection<SiteDataItem> _items= new ObservableCollection<SiteDataItem>();
   public ObservableCollection<SiteDataItem> Items
   {
       get { return this._items; }
   }
}

在我的页面加载状态下，我执行以下操作。我已经验证了GetProvider都返回了ProviderDateItem，并且GetSites返回了一个SiteBateItem的集合
。

protected override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)
{
    this.DefaultViewModel["Provider"] = SampleProviderDataSource.GetProvider("1");
    this.DefaultViewModel["Sites"] = SampleSitesDataSource.GetSites();
}

然后在我的XAML中，我有以下标记。  d：DataContext正在指向Binding to Provider，数据显示在设计元素中。 我甚至可以通过更改传递给GetProviders
的参数来更改我访问的提供商，并在设计模式中显示正确的数据。 但是，当我运行应用程序时，StackPanel中没有显示任何内容。 我曾尝试使用< StackPanel.Resources>，< ControlPresenter>以及我在网上找到的其他一些建议。 但是没有什么
我尝试工作，其中大多数提供与此处发布的代码相同的结果。 这可能不难做到，我敢打赌，这只是一件非常简单的事情。我想错过。 

Then in my XAML I have the following markup.  The d:DataContext is working pointing Binding to Provider and the data shows in the design element.  I can even change which provider I an accessing by changing the parameter passed to GetProviders and the correct data shows up in design mode.  But, when I run the application nothing show up in the StackPanel.  I have tried to use <StackPanel.Resources>, <ControlPresenter> and some other suggestions I found online.  But nothing I try works and most of them deliver the same results as the code posted here.  This cannot be that hard to do and I bet it is just something really simple I am missing. 

<StackPanel x:Name="selectedProviderPanel" Grid.Column="0" Grid.Row="1" Margin="10,5,10,-9" Grid.RowSpan="2" 
   DataContext="Provider"
   d:DataContext="{Binding Provider, Source={d:DesignInstance Type=data:SampleSitesDataSource, IsDesignTimeCreatable=True}}">
            
   <TextBlock Text="{Binding Name}" Margin="10,0,10,20" Style="{StaticResource SubheaderTextStyle}" MaxHeight="60"/>
   <Image Source="{Binding Image}" Height="254" Margin="10,0,10,20" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>
   <TextBlock Text="{Binding Url}" Margin="10,0,10,5" Style="{StaticResource BodyTextStyle}"/>
   <TextBlock Text="{Binding SupportNumber}" Margin="10,0,10,5" Style="{StaticResource BodyTextStyle}"/>
</StackPanel>

我对XAML很陌生并且令人沮丧我无法弄清楚这一点。如果这是一个Windows或Web应用程序，我可以很容易地做到这一点。任何帮助将不胜感激，我已经浪费了4-6个小时试图通过试用
和错误来解决这个问题。

I am pretty new to XAML and it is getting frustrating I cannot figure this out. If this was a windows or web application I could do this really easy. Any help will be appreciated, I have wasted 4-6 hours trying to figure this out on my own through trial and error.

谢谢你
S. Shawn Mehaffie

Thanks
S. Shawn Mehaffie

 

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推荐答案

要测试您的绑定尝试  此 。 DefaultViewModel [ " Provider" ]
= 新网站（）。提供商;

To test your binding try  this.DefaultViewModel["Provider"] = new Sites().Provider;

然后检查，但设置： 

Then check but setting: 

var  provider = SampleProviderDataSource 。 GetProvider <跨度>（ <跨度>" 1" <跨度>）; （检查提供商的价值）

然后 此 。 DefaultViewModel [ " Provider" ]
=提供商

var provider = SampleProviderDataSource.GetProvider("1"); (check value of provider)
and then this.DefaultViewModel["Provider"] = provider

查看绑定是否正确，Name，Image，Url& SupportNumber是ProviderDataItem的所有属性吗？ （不是字段，不是私有或受保护，而是在setter中实现INotifyPropertyChange PropertyChanged事件的公共属性）。

Looking at the binding is it correct that Name, Image, Url & SupportNumber are all properties of ProviderDataItem? (not fields, not private or protected but public properties that implement INotifyPropertyChange PropertyChanged event in the setter).

真的很遗憾微软已经创建了这些在培训人员时打破MVVM模式的模板模板新的XAML在坏习惯和使调试成为一场噩梦。大多数在XAML中工作的开发人员都会转储模板并绑定一个可测试的MVVM设计。

It is really unfortunate Microsoft has created these fudgy templates that break MVVM pattern as they train people new it XAML in bad habits and make debugging a nightmare. Most devs working in XAML dump the template and bind up a testable MVVM design.

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