为什么不能在Silverlight 4中绑定DataGridTemplateColumn的Visiblity？ [英] Why can I not bind the Visiblity of a DataGridTemplateColumn in Silverlight 4?

问题描述

似乎不可能在Silverlight 4中绑定DataGridTemplateColumn的visibility属性。我做了一些谷歌搜索，似乎有几个帖子表明它是做与事实上它不是DependencyObject ，以及这会在SL4中如何变化，但是这似乎不是这样的。

It seems that it is not possible to bind the visibility property of a DataGridTemplateColumn in Silverlight 4 still. I did some Googling and there seem to be a few posts suggesting it was to do with the fact that it was not a DependencyObject and how this would change in SL4 but it does not seem to be the case.

为了解决这个问题，我在datagrid加载的事件的代码中做到这一点，但是我很好奇为什么这样是这样吗？

To work around it, I do it in the code behind of the datagrid loaded event, but I am curious as to why this is the case?

这是我得到的错误消息（转换器返回Visibility值）：

Here is the error message I get (with a converter that returns a Visibility value):

{System.ArgumentException: Object of type 'System.Windows.Data.Binding' cannot be converted to type 'System.Windows.Visibility'.
   at System.RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast)
   at System.RuntimeType.CheckValue(Object value, Binder binder, CultureInfo culture, BindingFlags invokeAttr)
   at System.Reflection.MethodBase.CheckArguments(Object[] parameters, Binder binder, BindingFlags invokeAttr, CultureInfo culture, Signature sig)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, Object[] index, CultureInfo culture)
   at System.Reflection.RuntimePropertyInfo.SetValue(Object obj, Object value, Object[] index)
   at MS.Internal.XamlMemberInfo.SetValue(Object target, Object value)
   at MS.Internal.XamlManagedRuntimeRPInvokes.SetValue(XamlTypeToken inType, XamlQualifiedObject& inObj, XamlPropertyToken inProperty, XamlQualifiedObject& inValue)}

推荐答案

DataGridTemplateColumn 从 DependencyObject 派生，它的Visibility属性没有定义一个 DependencyProperty 。实际上它没有定义任何依赖属性，因此你仍然无法获得绑定的任何东西。

Whilst the DataGridTemplateColumn does derive from DependencyObject it does not define a DependencyProperty for its Visibility property. In fact it does not define any dependency properties hence you still can't get anything to bind on it.

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