wpf 如何绑定到动态类型的属性？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/14866299/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to bind to a property of type dynamic?
提问by Michael Schnerring
public interface IClassA
{
string Description { get; set; }
// more IClassA specific definitions
}
public interface IClassB
{
string Description { get; set; }
// more IClassB specific definitions
}
public class ClassA : IClassA
{
public string Description { get; set; }
}
public class ClassB : IClassB
{
public string Description { get; set; }
}
This is the very simplified code. All classes lack of INotifyPropertyChangedimplementations for simplicity. Just watch all the code as if it was properly implementend.
这是非常简化的代码。INotifyPropertyChanged为简单起见，所有类都缺少实现。只需观看所有代码，就好像它已正确实现一样。
Putting Descriptioninto a base interface for IClassAand IClassBcan't be considered, yet, so I was curious about dynamicproperties bound via data binding in WPF. This is, what I have tried:
把Description成基本接口IClassA和IClassB可不予考虑，但，所以我好奇dynamic经由数据在WPF结合结合性质。这是，我已经尝试过：
public class CustomClass
{
public dynamic Instance { get; set; }
// passed instance is a ClassA or ClassB object
public CustomClass(dynamic instance)
{
Instance = instance;
}
}
My Xaml contains a TextBlock, which has its DataContext set to a CutomClassobject. If I change the Instanceproperty's type to e.g. IClassA and fill it properly, everything works as expected. Not with dynamicthough.
我的 Xaml 包含一个TextBlock，它的 DataContext 设置为一个CutomClass对象。如果我将Instance属性的类型更改为例如 IClassA 并正确填充它，一切都会按预期工作。dynamic虽然不是。
<TextBlock Text="{Binding Instance.Description}" />
The Xaml Designer/ReSharper in VS2012 tells me:Cannot resolve property 'Description' in data context of type 'object'.
VS2012 中的 Xaml Designer/ReSharper 告诉我：Cannot resolve property 'Description' in data context of type 'object'。
Though CodeInstanceis described as type of dynamic. But the code compiled, so I thought that just might be a design-time issue. But the TextBlockremains empty.
虽然CodeInstance被描述为dynamic. 但是代码已编译，所以我认为这可能是设计时问题。但TextBlock空空如也。
I might misunderstand the principle dynamicin this case, I don't know. So the lack of search results by using Google might be caused by not exactly knowing what to search for.
dynamic在这种情况下，我可能会误解原理，我不知道。因此，使用 Google 搜索不到结果可能是因为不知道要搜索什么。
回答by sa_ddam213
You can bind to a dynamic property the same way as any property. So your problem must be manifesting somewhere else, or ReSharperis giving yet another unhelpful error, (hate that program)
您可以像绑定任何属性一样绑定到动态属性。所以你的问题一定是在其他地方出现，或者ReSharper是另一个无益的错误，（讨厌那个程序）
Dynamic binding Example:
动态绑定示例：
Xaml:
Xml：
<Window x:Class="WpfApplication7.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="104" Width="223" Name="UI">
<StackPanel DataContext="{Binding ElementName=UI}">
<TextBlock Text="{Binding MyProperty}" />
<TextBlock Text="{Binding MyObject.MyProperty}" />
</StackPanel>
</Window>
Code:
代码：
public partial class MainWindow : Window, INotifyPropertyChanged
{
public MainWindow()
{
InitializeComponent();
MyProperty = "Hello";
MyObject = new ObjectTest { MyProperty = "Hello" };
}
private dynamic myVar;
public dynamic MyProperty
{
get { return myVar; }
set { myVar = value; NotifyPropertyChanged("MyProperty"); }
}
private dynamic myObject;
public dynamic MyObject
{
get { return myObject; }
set { myObject = value; NotifyPropertyChanged("MyObject"); }
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string p)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(p));
}
}
}
public class ObjectTest
{
public string MyProperty { get; set; }
}
Result:
结果：
