为什么我无法在设计时解析 ContentControl ContentTemplateSelector?
(在运行时有效)
设计器(VS2010)显示异常:
System.Reflection.TargetInvocationException 调用的目标已引发异常。
和
System.NullReferenceException 对象引用未设置为对象的实例。
XAML:
<Window.Resources>
<DataTemplate x:Key="Temp1">
<TextBox TextWrapping="Wrap" Text="1" Height="20" Width="Auto"/>
</DataTemplate>
<local:TemplateSelector x:Key="mySelector"/>
<Grid>
<ContentControl ContentTemplateSelector="{StaticResource mySelector}">
<ContentControl.Content>
1
</ContentControl.Content>
</ContentControl>
</Grid>
</Window.Resources>
C#:
public class TemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
//int num = int.Parse(item.ToString());
Window win = Application.Current.MainWindow;
return win.FindResource("Temp1") as DataTemplate;//load template based on num...
}
}