asp.net-mvc – 传递给Html.ActionLink时在模型上序列化IList属

但是,如果您可以对类别名称施加一些约束,并且您能够以以下格式支持查询字符串：

http://www.test.com/search/index?keywords=bla&categories=Cat1|Cat2

那么你理论上可以将它插入Html.ActionLink,因为MVC使用TypeDescriptor,而TypeDescriptor在运行时又是可扩展的.提供以下代码以证明它是可能的,但我不建议使用它,至少在没有进一步重构的情况下.

话虽如此,您需要首先关联自定义类型描述提供程序：

[TypeDescriptionProvider(typeof(SearchModelTypeDescriptionProvider))]
public class SearchModel
{
    public string KeyWords { get; set; }
    public IList<string> Categories { get; set; }
}

提供程序的实现和覆盖Categories属性的属性描述符的自定义描述符：

class SearchModelTypeDescriptionProvider : TypeDescriptionProvider
{
    public override ICustomTypeDescriptor GetTypeDescriptor(
        Type objectType,object instance)
    {
        var searchModel = instance as SearchModel;
        if (searchModel != null)
        {
            var properties = new List<PropertyDescriptor>();

            properties.Add(TypeDescriptor.CreateProperty(
                objectType,"KeyWords",typeof(string)));
            properties.Add(new ListPropertyDescriptor("Categories"));

            return new SearchModelTypeDescriptor(properties.ToArray());
        }
        return base.GetTypeDescriptor(objectType,instance);
    }
}
class SearchModelTypeDescriptor : CustomTypeDescriptor
{
    public SearchModelTypeDescriptor(PropertyDescriptor[] properties)
    {
        this.Properties = properties;
    }
    public PropertyDescriptor[] Properties { get; set; }
    public override PropertyDescriptorCollection GetProperties()
    {
        return new PropertyDescriptorCollection(this.Properties);
    }
}

然后我们需要自定义属性描述符能够返回由MVC在内部调用的GetValue中的自定义值：

class ListPropertyDescriptor : PropertyDescriptor
{
    public ListPropertyDescriptor(string name)
        : base(name,new Attribute[] { }) { }

    public override bool CanResetValue(object component)
    {
        return false;
    }
    public override Type ComponentType
    {
        get { throw new NotImplementedException(); }
    }
    public override object GetValue(object component)
    {
        var property = component.GetType().GetProperty(this.Name);
        var list = (IList<string>)property.GetValue(component,null);
        return string.Join("|",list);
    }
    public override bool IsReadOnly { get { return false; } }
    public override Type PropertyType
    {
        get { throw new NotImplementedException(); }
    }
    public override void ResetValue(object component) { }
    public override void SetValue(object component,object value) { }
    public override bool ShouldSerializeValue(object component)
    {
        throw new NotImplementedException();
    }
}

最后证明它适用于模仿MVC路由值创建的示例应用程序：

static void Main(string[] args)
{
    var model = new SearchModel { KeyWords = "overengineering" };

    model.Categories = new List<string> { "1","2","3" };

    var properties = TypeDescriptor.GetProperties(model);

    var dictionary = new Dictionary<string,object>();
    foreach (PropertyDescriptor p in properties)
    {
        dictionary.Add(p.Name,p.GetValue(model));
    }

    // Prints: KeyWords,Categories
    Console.WriteLine(string.Join(",",dictionary.Keys));
    // Prints: overengineering,1|2|3
    Console.WriteLine(string.Join(",dictionary.Values));
}

该死的,这可能是我在SO所给出的最长的答案.