为什么我的一个WPF DataGrids中的一个授予“EditItem”不允许这个视图“例外？ [英] Why does one of MY WPF DataGrids give the "'EditItem' is not allowed for this view" exception?

问题描述

我已经阅读了所有可以在这里和关于这个例外的MS论坛上找到的问答，并尝试了我理解的大部分建议，还有其他几个。似乎这个异常可能会出现各种各样的原因。

与其他人一样，我将WPF DataGrid绑定到一个集合，当一个尝试编辑其中一个单元格。他们被设置为可写，集合是一个ObservableCollection，我已经实现了get和set处理程序，发送通知消息。

我没有尝试的建议是执行IList非通用接口的那些，因为我不知道该怎么做。此外，我有很多DataGrids绑定到我的应用程序中的各种列表和集合，这个工作，当它绑定到一个LINQ集合时，这个用于工作的。

请帮助我想知道我需要做什么。

数据网格是：

 < DataGrid Name =dgIngredientsMargin =567,32,0,44Width =360ItemsSource ={Binding}IsReadOnly =False
 AutoGenerateColumns =FalseHorizo​​ntalAlignment =LeftCanUserAddRows =FalseCanUserDeleteRows =False> 
< DataGrid.Columns> 
< DataGridTextColumn Width =63Header =PercentBinding ={Binding Preference}IsReadOnly =False/> 
< DataGridTextColumn SortDirection =DescendingWidth =301Header =IngredientBinding ={Binding Ingredient}IsReadOnly =TrueCanUserSort =TrueCanUserReorder =False/> 
< /DataGrid.Columns> 
< / DataGrid> 
  

正在编辑的列是不可读的列，首选项。

集合是：

  private ObservableCollection< RAM_Ingredient> MemberIngredientPrefs = new ObservableCollection< RAM_Ingredient>（）; 
  

绑定是：

  dgIngredients.DataContext = MemberIngredientPrefs.OrderBy（Ingredient，true）; 
  

RAM_Ingredient是：

  public class RAM_Ingredient：INotifyPropertyChanged 
  

等。

其中RAM_Ingredient.Preference是：

  private int _Preference; 
 public int首选项
 {
 get 
 {
 return _Preference; 
} 
 set 
 {
 //这是需要发送更改通知（并且不会在网格编辑中抛出异常！）：
 if（（_Preference ！= value））
 {
 SendPropertyChanging（）; 
 _Preference = value; 
 SendPropertyChanged（偏好）; 
} 
} 
} 
  

异常是： p>

  System.InvalidOperationException未处理
此视图不允许Message ='EditItem'。 
 Source = PresentationFramework 
 StackTrace：
在System.Windows.Controls.ItemCollection.System.ComponentModel.IEditableCollectionView.EditItem（对象项）
在System.Windows.Controls.DataGrid。 EditRowItem（Object rowItem）
在System.Windows.Controls.DataGrid.OnExecutedBeginEdit（ExecutedRoutedEventArgs e）
  

etc ...

解决方案

我也有这个问题，发现这里的一点是我们无法编辑在DataGrid中的IEnumerable中，只能列出一个列表。

因此，我们不需要创建一个新类，它也在具有匿名返回类型的LINQ查询上工作。它只需要一个列表。

这是我的代码示例：

  dtgPrdcts.ItemsSource = ProductLists.Select（Function（x）New With {.ListTitle = x.ListTitle，.ProductID = x.ProductID，.License =，.ForRemove = True}）ToList 
  

I have read all the Q&A I could find here and on the MS forums about this exception, and tried most of the suggestions that I understood, and a few others. It seems that this exception can come up for a wide range of causes.

As with others, I have a WPF DataGrid bound to a collection, which throws this exception when one tries to edit one of the cells. They are set to be write-able, the collection is an ObservableCollection, I've implemented get and set handlers which send notification messages.

The suggestions I haven't tried are the ones involving implementing IList's non-generic interface, because I have no idea what I would do to do that. Also, I have many DataGrids bound to various lists and collections in my app which work, and this one used to work when it was bound to a LINQ collection.

Please help me figure out what I need to do here.

The Data Grid is:

<DataGrid Name="dgIngredients" Margin="567,32,0,44" Width="360" ItemsSource="{Binding}" IsReadOnly="False"
           AutoGenerateColumns="False" HorizontalAlignment="Left" CanUserAddRows="False" CanUserDeleteRows="False">
    <DataGrid.Columns>
        <DataGridTextColumn Width="63" Header="Percent" Binding="{Binding Preference}" IsReadOnly="False" />
        <DataGridTextColumn SortDirection="Descending" Width="301" Header="Ingredient" Binding="{Binding Ingredient}" IsReadOnly="True" CanUserSort="True" CanUserReorder="False" />
    </DataGrid.Columns>
</DataGrid>

The column being edited is the non-read-only one, Preference.

The collection is:

private ObservableCollection<RAM_Ingredient> MemberIngredientPrefs = new ObservableCollection<RAM_Ingredient>();

The binding is:

dgIngredients.DataContext = MemberIngredientPrefs.OrderBy("Ingredient",true);

RAM_Ingredient is:

public class RAM_Ingredient : INotifyPropertyChanged 

etc.

Where RAM_Ingredient.Preference is:

private int _Preference;
public int Preference
{
    get
    {
        return _Preference;
    }
    set
    {
        // This is needed to send notification of changes (and to not throw an exception on grid edit!):
        if ((_Preference != value))
        {
            SendPropertyChanging();
            _Preference = value;
            SendPropertyChanged("Preference");
        }
    }
}

The exception is:

System.InvalidOperationException was unhandled
  Message='EditItem' is not allowed for this view.
  Source=PresentationFramework
  StackTrace:
       at System.Windows.Controls.ItemCollection.System.ComponentModel.IEditableCollectionView.EditItem(Object item)
       at System.Windows.Controls.DataGrid.EditRowItem(Object rowItem)
       at System.Windows.Controls.DataGrid.OnExecutedBeginEdit(ExecutedRoutedEventArgs e)

etc...

解决方案

I have also this problem, And found that the point here is that we can not edit a IEnumerable in a DataGrid, only a list can be edited.

therefore we didn't need to create a new class, its works also on a LINQ query with anonymous return type. it's need only to be a list.

here is a sample of my code:

 dtgPrdcts.ItemsSource= ProductLists.Select(Function(x) New With {.ListTitle = x.ListTitle, .ProductID = x.ProductID, .License = "", .ForRemove = True}).ToList

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