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我最近重构了一个DataTrigger。它以前的DataContext设置为ListBoxItem。现在它是一个ContentPresenter。WPF - 为触发器的setter设置DataContext
下面是代码：
<DataTemplate.Triggers>
<DataTrigger Value="True">
<DataTrigger.Binding>
<MultiBinding Converter="{StaticResource DisableWorkItemConverter}">
<Binding ElementName="MainForm" Path="PickedWorkItemID"/>
<Binding Path="WorkItemForColumn.Id"/>
</MultiBinding>
</DataTrigger.Binding>
<Setter Property="IsEnabled" Value="False"/>
<Setter Property="loc:Main.IsCurrentItemEnabledChanged" Value="True"/>
</DataTrigger>
</DataTemplate.Triggers>
在IsCurrentItemEnabledChanged的OnChange我可以看到，我可以在ListBoxItem用下面的代码获得（在后面的代码）：
listBoxItem = (ListBoxItem)Main.Instance.lstQueryResults.ItemContainerGenerator.
ContainerFromItem(((ContentPresenter)d).Content);
然而，我无法看到将DataContext设置为使我的Setter为IsEnabled将设置ListBoxItem的启用状态而不是ContentPresenter。
（我会做它的IsCurrentItemEnabledChanged的OnChange，但该财产已经是一个黑客攻击的一位，当触发设置为false也不会重新启用的项目。）
任何想法？
有人建议我提供更多的提供方面：
这里是我的模板XAML。
<DataTemplate x:Key="ColumnTemplate">
<Border Name="ItemBorder" BorderBrush="Black" BorderThickness="1" CornerRadius="2" Padding="2">
<WrapPanel>
<TextBlock Margin="0,0,5,0">
<TextBlock.Text>
<Binding Path="Name" Converter="{StaticResource GetVisibilityOfColumnTitles}"/>
</TextBlock.Text>
</TextBlock>
<TextBlock Text="{Binding Value}" Margin="0,0,10,0" FontWeight="Bold" />
</WrapPanel>
</Border>
</DataTemplate>
<DataTemplate x:Key="RowTemplate">
<Border x:Name="ItemBorder" BorderThickness="1" BorderBrush="#D4D4FF">
<Grid x:Name="ItemGrid" Width="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsPresenter}}, Path=ActualWidth}" ScrollViewer.CanContentScroll="True" Margin="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="30" />
</Grid.ColumnDefinitions>
<Grid.Background>
<Binding Path="WorkItemForColumn.Type" Converter="{StaticResource WorkItemTypeToColorConverter}" />
</Grid.Background>
<CheckBox VerticalAlignment="Center" Grid.Column="0" IsChecked="{Binding
RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBoxItem}},
Mode=TwoWay, Path=IsSelected}" Name="chkIsSelected" />
<ItemsControl Grid.Column="1" Margin="5,0,5,0" ItemsSource="{Binding}" ItemTemplate="{StaticResource ColumnTemplate}" >
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel Orientation="Horizontal"></WrapPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
<Button HorizontalAlignment="Right" x:Name="btnPick" Grid.Column="3" Style="{StaticResource roundButton}" Width="15" Height="15" Tag="{Binding WorkItemForColumn.Id}" Margin="5,0,10,0">
<Path Fill="DarkBlue">
<Path.Data>
<PathGeometry>
<PathFigure StartPoint="2,0" IsClosed="True">
<LineSegment Point="7,5"/>
<LineSegment Point="2,10"/>
</PathFigure>
<PathFigure StartPoint="2,2" IsClosed="True">
<LineSegment Point="5,5"/>
<LineSegment Point="2,8"/>
</PathFigure>
</PathGeometry>
</Path.Data>
</Path>
</Button>
</Grid>
</Border>
<DataTemplate.Triggers>
<DataTrigger Value="True">
<DataTrigger.Binding>
<MultiBinding Converter="{StaticResource DisableWorkItemConverter}">
<Binding ElementName="MainForm" Path="PickedWorkItemID"/>
<Binding Path="WorkItemForColumn.Id"/>
</MultiBinding>
</DataTrigger.Binding>
<Setter Property="IsEnabled" Value="False"/>
<Setter Property="loc:Main.IsCurrentItemEnabledChanged" Value="True"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>
这里是列表框中的XAML：
<ListBox ScrollViewer.HorizontalScrollBarVisibility="Disabled" Button.Click="PickWorkItem_Click" SelectionMode="Multiple" ItemTemplate="{StaticResource RowTemplate}" Name="lstQueryResults" SelectionChanged="lstQueryResults_SelectionChanged" >
<ListBox.Resources>
<Style TargetType="{x:Type ListBoxItem}">
<Style.Resources>
<SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black"/>
<SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black"/>
</Style.Resources>
</Style>
</ListBox.Resources>
</ListBox>
DataContext的是在代码中设置像这样：
private void ChangeQueryResultListSource(WorkItemCollection queryResults, bool b)
{
// Un-hook the selection event while we change the ItemsSource
Form.ToggleOnSelectEvent(false);
// This sets the DataContext
QueryDisplay = GetDisplayValues(queryResults);
Form.QueryResultListSource = QueryDisplay;
// Rewire the selection events back in
Form.ToggleOnSelectEvent(true);
foreach (WorkItem item in Pad.Keys)
{
Form.SelectQueryResultItem(item);
}
}
private List<List<WorkItemColumn>> GetDisplayValues(WorkItemCollection queryResults)
{
var result = new List<List<WorkItemColumn>>();
foreach (WorkItem workItem in queryResults)
{
var row = GetQueryColumns(queryResults.DisplayFields, workItem);
result.Add(row);
}
return result;
}
private List<WorkItemColumn> GetQueryColumns(DisplayFieldList fields, WorkItem workItem)
{
var row = new List<WorkItemColumn>();
foreach (FieldDefinition column in fields)
{
var workItemColumn = new WorkItemColumn { Name = column.Name, Value = workItem[column.Name], WorkItemForColumn = workItem };
row.Add(workItemColumn);
}
return row;
}
WorkItemColumn是一个名称 - 值对一类和对数据的引用（一个WorkItem对象）。
缩小了一点，显示出周围的代码，显示整个'DataTemplate'和显示正在使用它的控件。 – 2009-12-29 20:29:26
添加了所需的代码。感谢您看看这个。 – Vaccano 2009-12-29 21:04:09
我可能是唯一一个，但我有点困惑你的问题。 “但是，我无法设置DataContext，因此我的Setter for IsEnabled将设置ListBoxItem而不是ContentPresenter的启用状态。” – Ragepotato 2009-12-29 21:11:02