如何创建只读依赖属性？

Question

如何创建只读依赖属性？这样做的最佳做法是什么？

具体来说,最让我感到困惑的是没有实施的事实

DependencyObject.GetValue()  

以a System.Windows.DependencyPropertyKey为参数.

System.Windows.DependencyProperty.RegisterReadOnly返回一个D ependencyPropertyKey对象而不是一个DependencyProperty.那么如果你不能对GetValue进行任何调用,你应该怎么访问你的只读依赖属性？或者你应该以某种方式将其DependencyPropertyKey转换为普通的旧DependencyProperty对象？

建议和/或代码将非常感谢!

Answer 1

实际上很简单(通过RegisterReadOnly):

public class OwnerClass : DependencyObject // or DependencyObject inheritor
{
    private static readonly DependencyPropertyKey ReadOnlyPropPropertyKey
        = DependencyProperty.RegisterReadOnly("ReadOnlyProp", typeof(int), typeof(OwnerClass),
            new FrameworkPropertyMetadata(default(int),
                FrameworkPropertyMetadataOptions.None));

    public static readonly DependencyProperty ReadOnlyPropProperty
        = ReadOnlyPropPropertyKey.DependencyProperty;

    public int ReadOnlyProp
    {
        get { return (int)GetValue(ReadOnlyPropProperty); }
        protected set { SetValue(ReadOnlyPropPropertyKey, value); }
    }

    //your other code here ...
}

只有在private/protected/internal代码中设置值时才使用密钥.由于受保护的ReadOnlyProp二传手,这对您来说是透明的.