问题描述
作为一个例子采取以下code:
As an example take the following code:
public enum ExampleEnum { FooBar, BarFoo }
public class ExampleClass : INotifyPropertyChanged
{
private ExampleEnum example;
public ExampleEnum ExampleProperty
{ get { return example; } { /* set and notify */; } }
}
我希望有一个数据绑定属性ExampleProperty到一个ComboBox,这样它就会显示选项foobar如果和BarFoo,并在工作模式下双向。最理想我希望我的组合框的定义看起来是这样的:
I want a to databind the property ExampleProperty to a ComboBox, so that it shows the options "FooBar" and "BarFoo" and works in mode TwoWay. Optimally I want my ComboBox definition to look something like this:
<ComboBox ItemsSource="What goes here?" SelectedItem="{Binding Path=ExampleProperty}" />
目前,我有处理程序ComboBox.SelectionChanged和ExampleClass.PropertyChanged装在我的窗口,在这里我做事件手动绑定。
Currently I have handlers for the ComboBox.SelectionChanged and ExampleClass.PropertyChanged events installed in my Window where I do the binding manually.
有没有更好的或某种规范的方法?你通常会用转换器和你将如何填充正确的价值观的组合框?我甚至不希望开始与国际化现在。
Is there a better or some kind of canonical way? Would you usually use Converters and how would you populate the ComboBox with the right values? I don't even want to get started with i18n right now.
修改
所以,一个问题是回答:我如何填充组合框与正确的价值观
So one question was answered: How do I populate the ComboBox with the right values.
通过从静态Enum.GetValues方法的ObjectDataProvider的检索枚举值作为字符串列表:
Retrieve Enum values as a list of strings via an ObjectDataProvider from the static Enum.GetValues method:
<Window.Resources>
<ObjectDataProvider MethodName="GetValues"
ObjectType="{x:Type sys:Enum}"
x:Key="ExampleEnumValues">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="ExampleEnum" />
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
</Window.Resources>
这我可以作为一个的ItemsSource为我的组合框使用
<ComboBox ItemsSource="{Binding Source={StaticResource ExampleEnumValues}}"/>
推荐答案
您可以创建自定义标记扩展。
You can create a custom markup extension.
使用示例:
enum Status
{
[Description("Available.")]
Available,
[Description("Not here right now.")]
Away,
[Description("I don't have time right now.")]
Busy
}
<ComboBox
ItemsSource="{Binding Source={my:Enumeration {x:Type my:Status}}}"
DisplayMemberPath="Description"
SelectedValue="{Binding CurrentStatus}"
SelectedValuePath="Value" />
和实施
public class EnumerationExtension : MarkupExtension
{
private Type _enumType;
public EnumerationExtension(Type enumType)
{
if (enumType == null)
throw new ArgumentNullException("enumType");
EnumType = enumType;
}
public Type EnumType
{
get { return _enumType; }
private set
{
if (_enumType == value)
return;
var enumType = Nullable.GetUnderlyingType(value) ?? value;
if (enumType.IsEnum == false)
throw new ArgumentException("Type must be an Enum.");
_enumType = value;
}
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
var enumValues = Enum.GetValues(EnumType);
return (
from object enumValue in enumValues
select new EnumerationMember{
Value = enumValue,
Description = GetDescription(enumValue)
}).ToArray();
}
private string GetDescription(object enumValue)
{
var descriptionAttribute = EnumType
.GetField(enumValue.ToString())
.GetCustomAttributes(typeof (DescriptionAttribute), false)
.FirstOrDefault() as DescriptionAttribute;
return descriptionAttribute != null
? descriptionAttribute.Description
: enumValue.ToString();
}
public class EnumerationMember
{
public string Description { get; set; }
public object Value { get; set; }
}
}
这篇关于数据绑定一个枚举属性在WPF组合框的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!