c# - 如何检查依赖对象是否包含依赖属性？

Question

本质上，我想要一些简单的反射，其中我有一个任意的 DependencyProperty 作为参数。如果 DependencyProperty 由 PlaneProjection 的/属性定义，我会有一个特例(例如，在 if 语句中)。我已经完成了一些简单的 GetType() fandangling，但没有像 MemberType 这样的预期 setter/getter 。

public void SomeFunc(DependencyProperty dp)
{
    // if dp is a dependency property of plane projection, do something
    // would maybe look like PlaneProjection.hasProperty(dp)
}

Answer 1

使用扩展方法尝试此代码:

public static class Helpers
{
    public static DependencyProperty FindDependencyProperty(this DependencyObject target, string propName)
    {
        FieldInfo fInfo = target.GetType().GetField(propName, BindingFlags.Static | BindingFlags.FlattenHierarchy | BindingFlags.Public);

        if (fInfo == null) return null;

        return (DependencyProperty)fInfo.GetValue(null);
    }

    public static bool HasDependencyProperty(this DependencyObject target, string propName)
    {
        return FindDependencyProperty(target, propName) != null;
    }

    public static string GetStaticMemberName<TMemb>(Expression<Func<TMemb>> expression)
    {
        var body = expression.Body as MemberExpression;

        if (body == null) throw new ArgumentException("'expression' should be a member expression");

        return body.Member.Name;
    }
}

用法:

planeProjection1.HasDependecyProperty(
    Helpers.GetStaticMemberName(() => PlaneProjection.CenterOfRotationXProperty));