EF5 Grdiview仅计数&只读 [英] EF5 Grdiview only Count & ReadOnly

问题描述

在Entity Framework中，当我添加从数据源拖动时，网格视图仅显示Count&是只读列，我也尝试过手动分配datsource，但仍然无法正常工作。

In Entity Framework When I add Drag from Datasource the grid view only shows Count & Is Read Only Column, I have also tried manually assigning datsource but still not working.

推荐答案

通过一些研究，我找到了解决方案。

Through some researh I have found a solution.

BTW我首先使用代码。

BTW I am using code first.

在父实体中，我将子属性从列表更改为ObservableCollection 。
我也将命名空间System.Collections.ObjectModel添加到类中。

In the parent entity I changed the child property from list to ObservableCollection. I also added the namespace System.Collections.ObjectModel to my class.

Old：公共可重写属性PageElements作为List（Of PageElement ）

新功能：作为ObservableCollection（Of PageElement）的公共可重写属性PageElements

删除现有数据源（和表单中的控件）。然后重新创建将数据源拖到窗体上。

Delete your existing datasource (and controls from the form). Then recreate your datasource drag to the form.

您可能需要创建一个名为ObservableListSource的类，并使用该类代替ObservableCollection，但似乎已解决了原始问题。

You may need to create a class called ObservableListSource and use that instead of ObservableCollection, but it seems to have cleared up the original problem so far.

这里是我在网上其他地方找到的ObservableListSource的建议定义。

Here a suggested definition for the ObservableListSource I found elsewhere on the web.

Public Class ObservableListSource(Of T As Class)
     Inherits ObservableCollection(Of T)
     Implements IListSource
     Private _bindingList As IBindingList

    Private ReadOnly Property ContainsListCollection() As Boolean Implements IListSource.ContainsListCollection
         Get
             Return False
         End Get
     End Property

    Private Function GetList() As IList Implements IListSource.GetList
         Return If(_bindingList, (InlineAssignHelper(_bindingList, Me.ToBindingList())))
     End Function
     Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, value As T) As T
         target = value
         Return value
     End Function
EndCLass

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