我有 MeetingViewModelList 绑定到 DataGrid 。 每个 MeetingViewModel 都有一个 DocumentViewModelList 绑定到DataGrid的 DataGridTemplateColumn 中的 ListBox 。
DocumentViewModel的IsSelected属性绑定到ListBox的Item属性IsSelected。
输出控制台中没有绑定错误。
DocumentViewModel中的删除文档按钮检查其CanExecute方法:
private bool CanDeleteDocument()
{
return _isSelected;
}
当我在ListBox中选择 FIRST 项时,将启用“删除”按钮。 当我在ListBox中选择第2个,第3个等项时,删除按钮总是被禁用。
我尝试仅粘贴重要代码并裁剪其他内容:
我刚刚尝试使用ListBox重建场景 - 不是DataGrid的一部分 - 我得到了相同的行为:/
我会对任何暗示感到高兴:)
XAML :
<DataGrid VirtualizingStackPanel.VirtualizationMode="Recycling"
ScrollViewer.CanContentScroll="False"
CanUserResizeRows="True"
VerticalScrollBarVisibility="Auto"
ItemsSource="{Binding MeetingViewModelList}"
AutoGenerateColumns="False"
x:Name="DailyGrid"
Height="580"
SelectionMode="Single"
CanUserSortColumns="False"
Background="#FF2DCE2D"
CanUserAddRows="False"
HeadersVisibility="All"
RowHeaderWidth="40"
RowHeight="200" >
<!--Content-->
<DataGridTemplateColumn Width="0.5*" Header="Content">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Helper:RichTextBox LostFocus="RTFBox_LostFocus" VerticalScrollBarVisibility="Auto" x:Name="RTFBox" Text="{Binding Content,IsAsync=True}" AcceptsReturn="True" AutoWordSelection="False" AllowDrop="False" SelectionBrush="#FFAC5BCB" HorizontalScrollBarVisibility="Hidden">
<Helper:RichTextBox.TextFormatter>
<Helper:RtfFormatter />
</Helper:RichTextBox.TextFormatter>
</Helper:RichTextBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<!--Documents-->
<DataGridTemplateColumn Visibility="{Binding Source={StaticResource spy}, Path=DataContext.DocumentsVisible}" IsReadOnly="True" Width="125" Header="Attachments">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<StackPanel Background="Green" DataContext="{Binding DocumentViewModelList}" Orientation="Vertical" >
<ListBox SelectionMode="Single" VirtualizingStackPanel.IsVirtualizing="False"
Height="100"
Width="Auto"
Focusable="True"
ScrollViewer.HorizontalScrollBarVisibility="Auto"
ScrollViewer.VerticalScrollBarVisibility="Auto"
Grid.Row="1"
Name="documentListBox"
BorderThickness="1"
ItemsSource="{Binding}"
Visibility="{Binding ElementName=documentListBox,Path=HasItems, Converter={StaticResource boolToVisibilityConverter}}"
>
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Path=Name}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
<ListBox.ItemContainerStyle>
<Style TargetType="{x:Type ListBoxItem}">
<Setter Property="IsSelected" Value="{Binding Mode=TwoWay, Path=IsSelected}" />
</Style>
</ListBox.ItemContainerStyle>
</ListBox>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch">
<Button Command="{Binding Path=DeleteDocumentCommand}" HorizontalAlignment="Stretch" Content="Delete" />
<Button Command="{Binding Path=AddDocumentCommand}" HorizontalAlignment="Stretch" Content="Add" />
<Button Command="{Binding Path=OpenDocumentCommand}" HorizontalAlignment="Stretch" Content="Open" />
</StackPanel>
</StackPanel>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
ReportingViewModel(控制器):
public class ReportingViewModel : ViewModelBase
{
private ObservableCollection<MeetingViewModel> _meetingViewModelList;
public ReportingViewModel ()
{
}
public ObservableCollection<MeetingViewModel> MeetingViewModelList
{
get { return _meetingViewModelList; }
set
{
_meetingViewModelList= value;
this.RaisePropertyChanged("MeetingViewModelList");
}
}
}
MeetingViewModel:
public class MeetingViewModel: ViewModelBase
{
private ObservableCollection<DocumentViewModel> _documentViewModelList = new ObservableCollection<DocumentViewModel>();
private Meeting _meeting;
public MeetingViewModel(Meeting meeting)
{
_meeting= meeting;
_meeting.Documents.ForEach(doc => DocumentViewModelList.Add(new DocumentViewModel(doc)));
}
public ObservableCollection<DocumentViewModel> DocumentViewModelList
{
get { return _documentViewModelList; }
set
{
_documentViewModelList = value;
this.RaisePropertyChanged("DocumentViewModelList");
}
}
public string Content
{
get { return _meeting.Content; }
set
{
if (_meeting.Content == value)
return;
_meeting.Content = value;
this.RaisePropertyChanged("Content");
}
}
}
DocumentViewModel:
public class DocumentViewModel : ViewModelBase
{
private Document _document;
private RelayCommand _deleteDocumentCommand;
private RelayCommand _addDocumentCommand;
private RelayCommand _openDocumentCommand;
public DocumentViewModel(Document document)
{
_document = document;
}
private void DeleteDocument()
{
throw new NotImplementedException();
}
private bool CanDeleteDocument()
{
return _isSelected;
}
private void AddDocument()
{
}
private void OpenDocument()
{
}
public RelayCommand DeleteDocumentCommand
{
get { return _deleteDocumentCommand ?? (_deleteDocumentCommand = new RelayCommand(() => DeleteDocument(), () => CanDeleteDocument())); }
}
public RelayCommand AddDocumentCommand
{
get { return _addDocumentCommand ?? (_addDocumentCommand = new RelayCommand(() => AddDocument())); }
}
public RelayCommand OpenDocumentCommand
{
get { return _openDocumentCommand ?? (_openDocumentCommand = new RelayCommand(() => OpenDocument())); }
}
private bool _isSelected;
public bool IsSelected
{
get { return _isSelected; }
set
{
if (_isSelected == value)
return;
_isSelected = value;
this.RaisePropertyChanged("IsSelected");
}
}
public string Name
{
get { return _document.DocumentName; }
set
{
if (_document.DocumentName == value)
return;
_document.DocumentName = value;
this.RaisePropertyChanged("Name");
}
}
}
答案 0 :(得分:0)
我确信它可以以这种方式工作,但是以另一种方式跟踪所选项目会不会更容易?例如,绑定到包装实际集合的ICollectionView(例如ListCollectionView)允许使用内置选择跟踪机制(ICollectionView的CurrentItem)。或者,您可以使用ListBox的SelectedValue和SelectedValuePath。
答案 1 :(得分:0)
我认为问题是删除命令不知道选择已经改变。
将CanDeleteChanged添加到relay命令并在此之后引发它.RaisePropertyChanged(“IsSelected”)。我之前遇到过与Prism应用程序类似的问题。
EDIT。事实上,您应该添加CanDeleteChanged并在其中放置一个断点,并查看它是否在您预期到之时被调用。
抱歉,我的意思是删除中继命令的CanExecuteChanged事件。你的代码应该在某个地方声明一个relay命令。为了这里的信息,它是
public class RelayCommand:ICommand { #region Fields
readonly Action<object> _execute;
readonly Predicate<object> _canExecute;
#endregion // Fields
#region Constructors
public RelayCommand(Action<object> execute)
: this(execute, null)
{
}
public RelayCommand(Action<object> execute, Predicate<object> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion // Constructors
#region ICommand Members
[DebuggerStepThrough]
public bool CanExecute(object parameter)
{
return _canExecute == null ? true : _canExecute(parameter);
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public void Execute(object parameter)
{
_execute(parameter);
}
#endregion // ICommand Members
}