MarkupExtension:将简单属性转换为DependencyProperty

Question

我正在使用WPFLocalizationExtension (在CodePlex上提供)来本地化我的WPF应用程序中的字符串。这个简单的MarkupExtension在下面这样的简单场景中工作得很好：

<Button Content="{lex:LocText MyApp:Resources:buttonTitle}" />

但当我尝试一些更复杂的东西时，我就卡住了，比如：

<Window Title="{lex:LocText MyApp:Resources:windowTitle, FormatSegment1={Binding Version}}" />

(使用资源windowTitle = "MyApp v{0}")。

因为FormatSegment1是一个普通的INotifyPropertyChange属性，所以我不能给它绑定任何东西。如果FormatSegment1是一个DependencyProperty，这是可能的，所以我下载了源代码并尝试对其进行修补。

我修改过了

[MarkupExtensionReturnType(typeof(string))]
public class LocTextExtension : BaseLocalizeExtension<string>
{

    // ---- OLD property

    //public string FormatSegment1
    //{
    //    get { return this.formatSegments[0]; }
    //    set
    //    {
    //        this.formatSegments[0] = value;
    //        this.HandleNewValue();
    //    }
    //}

    // ---- NEW DependencyProperty

    /// <summary>
    /// The <see cref="FormatSegment1" /> dependency property's name.
    /// </summary>
    public const string FormatSegment1PropertyName = "FormatSegment1";

    /// <summary>
    /// Gets or sets the value of the <see cref="FormatSegment1" />
    /// property. This is a dependency property.
    /// </summary>
    public string FormatSegment1
    {
        get
        {
            return (string)GetValue(FormatSegment1Property);
        }
        set
        {
            SetValue(FormatSegment1Property, value);
        }
    }

    /// <summary>
    /// Identifies the <see cref="FormatSegment1" /> dependency property.
    /// </summary>
    public static readonly DependencyProperty FormatSegment1Property = DependencyProperty.Register(
        FormatSegment1PropertyName,
        typeof(string),
        typeof(LocTextExtension),
        new UIPropertyMetadata(null));

    // ...
}

BaseLocalizeExtension类继承自MarkupExtension

public abstract class BaseLocalizeExtension<TValue> : MarkupExtension, IWeakEventListener, INotifyPropertyChanged

当我构建的时候，我得到了通常的"GetValue/SetValue does not exist in current context"错误。我试图让BaseLocalizeExtension类继承自DependencyObject，但是我得到了大量的错误。

有没有办法在MarkupExtension中使用xaml可绑定的DependencyProperty (或者也是可绑定的内容)？

谢谢你的提示

Answer 1

你可以选择附加属性，在我看来，这是你唯一的选择。

例如：

public static readonly DependencyProperty FormatSegment1Property = DependencyProperty.RegisterAttached(
        "FormatSegment1", typeof(string), typeof(LocTextExtension), new PropertyMetadata(default(string)));

public static void SetFormatSegment1(DependencyObject element, string value)
{
    element.SetValue(FormatSegment1Property, value);
}

public static string GetFormatSegment1(DependencyObject element)
{
    return (string)element.GetValue(FormatSegment1Property);
}

。

<Window Title="{lex:LocText MyApp:Resources:windowTitle}" lex:LocText.FormatSegment1="{Binding Version}" />