如何绑定查找组合框？ [英] How do I bind a lookup combobox?

问题描述

我的WPF4组合框下拉列表错误地显示了我的EF4实体的类名。以下是相关的XAML：

 < Window.Resources> 
< CollectionViewSource x：Key =myEntitiesViewSource/> 
< /Window.Resources> 
 
< ComboBox ItemsSource ={Binding Source = {StaticResource myEntitiesViewSource}}DisplayMemberPath =CategoryDe​​scriptionSelectedValuePath =CategoryID/> 
  

以下是我的Window_Loaded事件中的代码：

  var categoryList = from p in _context.Categories 
 orderby p.CategoryNumber 
 select p; 
 
 System.Windows.Data.CollectionViewSource myEntitiesViewSource =（（System.Windows.Data.CollectionViewSource）（this.FindResource（myEntitiesViewSource）））; 
 //通过设置CollectionViewSource.Source属性来加载数据：
 myEntitiesViewSource.Source = categoryList; 
  

我的数据库具有一个名为ProjectCategories的连接表的项目和类别之间的多对多关系。类别实体被自动创建为单个实体来表示两个数据库表：

1）包含ID，CategoryDe​​scription和CategoryNumber的类别的查找表和

2）仅包含两个字段的连接表ProjectCategories - Projects and Categories表中的ID。实体模型与我的WPF窗口生活在一个单独的项目中。

我的目标是允许用户从下拉列表中选择一个CategoryDe​​scription，然后单击添加类别按钮将所选类别添加到ProjectCategories的单独列表中。使用当前代码，我在组合框文本区域中看到正确的CategoryDe​​scription，但是下拉列表仅显示实体类名称类别（之前是它的命名空间）！

如何使这个简单的查找组合框正确绑定并显示CategoryDe​​scriptions和CategoryID的SelectedValue的列表？注意：如果可行，我将接受仅在代码中使用的代码，不包括在XAML中的CollectionViewSource。 p>

谢谢！

解决方案

Nevermind。我问了这个问题，自己回答了。我的代码或XAML没有任何错误。 问题是由于使用第三方主题来创建我的控件。一旦我删除了主题，组合框绑定问题就消失了。更多详情看到这篇文章。

My WPF4 combobox dropdown list is incorrectly displaying the class name of my EF4 entity. Here is the relevant XAML:

<Window.Resources>
    <CollectionViewSource x:Key="myEntitiesViewSource"/>
</Window.Resources>

<ComboBox ItemsSource="{Binding Source={StaticResource myEntitiesViewSource}}" DisplayMemberPath="CategoryDescription" SelectedValuePath="CategoryID" />

Here is the code in my Window_Loaded event:

var categoryList = from p in _context.Categories
                  orderby p.CategoryNumber
                  select p;

System.Windows.Data.CollectionViewSource myEntitiesViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("myEntitiesViewSource")));
// Load data by setting the CollectionViewSource.Source property:
myEntitiesViewSource.Source = categoryList;

My database has a many to many relationship between Projects and Categories with a join table called ProjectCategories. The Categories entity was automagically created as a single entity to represent two database tables:

1) the lookup table of Categories containing an ID, CategoryDescription and CategoryNumber and

2) the join table ProjectCategories containing only two fields - the IDs from the tables Projects and Categories. The entity model lives in a separate project from my WPF window.

My goal is to allow the user to select a CategoryDescription from the dropdown list, then click an Add Category button to add the selected Category to a separate list of ProjectCategories. With the current code I see the correct CategoryDescription in the combobox text area but the dropdown list displays only the entity class name Categories (preceded by it's namespace) multiple times!

How do I make this simple lookup combobox bind correctly and display a list of CategoryDescriptions and a SelectedValue of CategoryID? Note: I'd accept a code only approach leaving out the CollectionViewSource in XAML if it's possible.

Thanks!

解决方案

Nevermind. I asked this question and have answered it myself. There was nothing wrong with my code or XAML. The problem was caused by the use of a third party theme to style my controls. Once I removed the theme the combobox binding problem went away. For more details see this post.

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