1
나는 미치게 만드는 문제가 있습니다.DataTemplate의 DependencyProperty가 작동하지 않습니다.
나는 extensionclass에 종속 속성 인 Uid를 가지고 있습니다. 이 정적 "언어"문자열을 설정하려면 (tools : TranslateExtension.Uid = "MAINWINDOW_ARTICLES"). 그런 다음 Text = "{tools : Translate}"를 사용하여 설정된 언어에 대한 조회를 트리거합니다.
바인딩을 설정하는 ProvideValue 메소드를 호출합니다. 아래에서 두 번째 버튼과 같이 컨트롤에서 직접 호출하면 모든 것이 올바르게 작동합니다. 그러나 DataTemplate 내에서이 작업을 수행하면 GetUid가 "MAINWINDOW_ARTICLES"대신 빈 문자열을 반환합니다. 이유를 이해할 수없는 것 같습니다. 어떤 아이디어?
실행 가능한 예를
아래 볼 수 있습니다 : 템플릿 시나리오에서<Window x:Class="DXSample.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:tools="clr-namespace:DXSample"
xmlns:System="clr-namespace:System;assembly=mscorlib"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<DataTemplate x:Key="template">
<TextBlock tools:TranslateExtension.Uid="MAINWINDOW_ARTICLES" Text="{tools:Translate}"/>
</DataTemplate>
</Window.Resources>
<StackPanel>
<Button ContentTemplate="{StaticResource template}"/>
<Button Content="{tools:Translate}" tools:TranslateExtension.Uid="MAINWINDOW_ARTICLES"/>
</StackPanel>
</Window>
[ContentProperty("Parameters")]
public class TranslateExtension : MarkupExtension
{
private DependencyProperty property;
private DependencyObject target;
private readonly Collection<BindingBase> parameters = new Collection<BindingBase>();
public Collection<BindingBase> Parameters
{
get { return parameters; }
}
private bool IsDataBound
{
get { return BindingOperations.IsDataBound(target, property); }
}
public static string GetUid(DependencyObject obj)
{
return (string)obj.GetValue(UidProperty);
}
public static void SetUid(DependencyObject obj, string value)
{
obj.SetValue(UidProperty, value);
}
public static readonly DependencyProperty UidProperty = DependencyProperty.RegisterAttached("Uid",
typeof(string),
typeof(TranslateExtension),
new UIPropertyMetadata(string.Empty));
public override object ProvideValue(IServiceProvider serviceProvider)
{
IProvideValueTarget service =
serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
if (service == null)
throw new InvalidOperationException("IProvideValueTarget service is unavailable");
DependencyProperty dependencyProperty = service.TargetProperty as DependencyProperty;
if (dependencyProperty == null)
throw new ArgumentException("Target property must be of type DependencyProperty");
DependencyObject dependencyObject = service.TargetObject as DependencyObject;
if (dependencyObject == null)
return this;
target = dependencyObject;
property = dependencyProperty;
BindDictionary();
return dependencyObject.GetValue(dependencyProperty);
}
private void element_Loaded(object sender, RoutedEventArgs e)
{
if (!IsDataBound)
BindDictionary();
}
private void element_Unloaded(object sender, RoutedEventArgs e)
{
if (IsDataBound)
BindingOperations.ClearBinding(target, property);
}
private void BindDictionary()
{
string uid = GetUid(target);
if (string.IsNullOrEmpty(uid))
{
Debug.WriteLine("UID NULL OR EMPTY");
return;
}
string vid = property.Name;
Binding binding = new Binding("Dictionary");
binding.Source = LanguageContext.Instance;
binding.Mode = BindingMode.TwoWay;
//LanguageConverter converter = new LanguageConverter(uid, vid);
if (parameters.Count == 0)
{
//binding.Converter = converter;
BindingOperations.SetBinding(target, property, binding);
}
else
{
MultiBinding multiBinding = new MultiBinding();
multiBinding.Mode = BindingMode.TwoWay;
//multiBinding.Converter = converter;
multiBinding.Bindings.Add(binding);
if (string.IsNullOrEmpty(uid))
{
Binding uidBinding = parameters[0] as Binding;
if (uidBinding == null)
throw new ArgumentException("Uid Binding parameter must be the first, and of type Binding");
}
foreach (Binding parameter in parameters)
multiBinding.Bindings.Add(parameter);
BindingOperations.SetBinding(target, property, multiBinding);
}
}
}
public class LanguageContext
{
static LanguageContext _languageContext;
public static LanguageContext Instance { get { if (_languageContext == null) _languageContext = new LanguageContext { Dictionary = "test string" }; return _languageContext; } }
public string Dictionary { get; set; }
}