在数据网格 wpf 中使用带有复选框控件的 ItemsSource 之前，项目集合必须为空
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Items collection must be empty before using ItemsSource with checkbox control in datagrid wpf
提问by Mark
This error only occurs when I add this following XAML code :
仅当我添加以下 XAML 代码时才会发生此错误：
<DataGridTemplateColumn Header="Ist aktiv" IsReadOnly="True">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsActiveBool}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid>
采纳答案by Sheridan
There are a number of possible reasons why you got this error, most (if not all) of which have already been discussed here on StackOverflow. Take a look at the following posts:
出现此错误的可能原因有很多，其中大部分（如果不是全部）已经在 StackOverflow 上讨论过。看看以下帖子：
Items collection must be empty before using ItemsSource in Silverlight
在 Silverlight 中使用 ItemsSource 之前，Items 集合必须为空
Error: Items collection must be empty before using ItemsSource
错误：在使用 ItemsSource 之前，Items 集合必须为空
Getting an “Items collection must be empty before using ItemsSource” with EF
使用 EF 获取“在使用 ItemsSource 之前必须为空的项目集合”
DataGridTemplateColumn : Items collection must be empty before using ItemsSource.
DataGridTemplateColumn ：在使用 ItemsSource 之前，Items 集合必须为空。
Items collection must be empty before using ItemsSource
在使用 ItemsSource 之前，Items 集合必须为空
If you don't find an answer in these posts, perhaps you could do your own search... it is generally preferable for SO users to search beforethey ask questions here.
如果您在这些帖子中没有找到答案，也许您可以自己进行搜索……SO 用户通常最好在他们在这里提问之前先进行搜索。
回答by sm2mafaz
I also faced a similar problem for the first time, and I noticed you could even get this error message if you have forgot to add/enclose the
我也第一次遇到了类似的问题，我注意到如果您忘记添加/附上
<DataGrid.Columns> </DataGrid.Columns>
tags
标签
回答by Eric Ouellet
Just for information...
仅供参考...
I had the problem because I added this style which seems very strange:
我遇到了这个问题，因为我添加了这种看起来很奇怪的样式：
<Style TargetType="{x:Type DataGridCell}">
<EventSetter Event="PreviewMouseLeftButtonDown" Handler="DataGridCell_PreviewMouseLeftButtonDown" />
</Style>
回答by margaret
Here is my code! It works. Really, I forgot to put tags in an appropriate place.
这是我的代码！有用。真的，我忘了把标签放在合适的地方。
<DataGrid x:Name="CostsDataGrid" HorizontalAlignment="Left" Margin="307,98,0,0" VerticalAlignment="Top" Height="260" Width="313" AutoGenerateColumns="False" MinColumnWidth="35" VerticalGridLinesBrush="#FF7A7878" HorizontalGridLinesBrush="#FF7A7878" RowHeight="35" Foreground="Black" PreviewMouseRightButtonDown="CostsDataGrid_PreviewMouseRightButtonDown" >
<DataGrid.Columns>
<DataGridTemplateColumn Header="состояние" Width="70" IsReadOnly="False">
<DataGridTemplateColumn.CellTemplate >
<DataTemplate>
<CheckBox IsChecked="{Binding Path=IsSelected, UpdateSourceTrigger=PropertyChanged}" Checked="OnChecked" Unchecked="OffChecked"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTextColumn Header="расход" Binding="{Binding name}" Width="121" IsReadOnly="True" />
<DataGridTextColumn Header="сумма" Binding="{Binding price}" Width="120" IsReadOnly="True" />
</DataGrid.Columns>
</DataGrid>
