在C中,将匿名类型转换为键/值数组?

这只需要一点点思考就可以完成。

var a = new { data1 = "test1", data2 = "sam", data3 = "bob" };
var type = a.GetType();
var props = type.GetProperties();
var pairs = props.Select(x => x.Name + "=" + x.GetValue(a, null)).ToArray();
var result = string.Join("&", pairs);

如果使用.NET 3.5 SP1或.NET 4,则可以(AB)使用 RouteValueDictionary 为此。它实现 IDictionary<string, object> 并且有一个接受 object 并将属性转换为键值对。

然后,通过循环键和值来构建查询字符串就很简单了。

以下是他们在RouteValueDictionary中的做法:

  private void AddValues(object values)
    {
        if (values != null)
        {
            foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(values))
            {
                object obj2 = descriptor.GetValue(values);
                this.Add(descriptor.Name, obj2);
            }
        }
    }

完整来源如下: http://pastebin.com/c1gQpBMG

@Kbrimington的解决方案是一个很好的扩展方法-我的案例返回了一个htmlstring

    public static System.Web.HtmlString ToHTMLAttributeString(this Object attributes)
    {
        var props = attributes.GetType().GetProperties();
        var pairs = props.Select(x => string.Format(@"{0}=""{1}""",x.Name,x.GetValue(attributes, null))).ToArray();
        return new HtmlString(string.Join(" ", pairs));
    }

我使用它将任意属性放到Razor MVC视图中。我从使用routeValueDictionary和循环结果的代码开始,但这要整洁得多。

我做了这样的事:

public class ObjectDictionary : Dictionary<string, object>
{
    /// <summary>
    /// Construct.
    /// </summary>
    /// <param name="a_source">Source object.</param>
    public ObjectDictionary(object a_source)
        : base(ParseObject(a_source))
    {

    }

    /// <summary>
    /// Create a dictionary from the given object (<paramref name="a_source"/>).
    /// </summary>
    /// <param name="a_source">Source object.</param>
    /// <returns>Created dictionary.</returns>
    /// <exception cref="ArgumentNullException">Thrown if <paramref name="a_source"/> is null.</exception>
    private static IDictionary<String, Object> ParseObject(object a_source)
    {
        #region Argument Validation

        if (a_source == null)
            throw new ArgumentNullException("a_source");

        #endregion

        var type = a_source.GetType();
        var props = type.GetProperties();

        return props.ToDictionary(x => x.Name, x => x.GetValue(a_source, null));
    }
}

基于@gwb关于使用 RouteValueDictionary ,我编写了这个递归函数来支持嵌套的匿名类型,并通过父类的键对这些嵌套参数进行前缀。

public static string EncodeHtmlRequestBody(object data, string parent = null) {
    var keyValuePairs = new List<string>();
    var dict = new RouteValueDictionary(data);

    foreach (var pair in dict) {
        string key = parent == null ? pair.Key : parent + "." + pair.Key;
        var type = pair.Value.GetType();
        if (type.IsPrimitive || type == typeof(decimal) || type == typeof(string)) {
            keyValuePairs.Add(key + "=" + Uri.EscapeDataString((string)pair.Value).Replace("%20", "+"));
        } else {
            keyValuePairs.Add(EncodeHtmlRequestBody(pair.Value, key));
        }
    }

    return String.Join("&", keyValuePairs);
}

示例用法:

var data = new {
    apiOperation = "AUTHORIZE",
    order = new {
        id = "order123",
        amount = "101.00",
        currency = "AUD"
    },
    transaction = new {
        id = "transaction123"
    },
    sourceOfFunds = new {
        type = "CARD",
        provided = new {
            card = new {
                expiry = new {
                    month = "1",
                    year = "20"
                },
                nameOnCard = "John Smith",
                number = "4444333322221111",
                securityCode = "123"
            }
        }
    }
};

string encodedData = EncodeHtmlRequestBody(data);

encodedData 变成:

"apiOperation=AUTHORIZE&order.id=order123&order.amount=101.00&order.currency=AUD&transaction.id=transaction123&sourceOfFunds.type=CARD&sourceOfFunds.provided.card.expiry.month=1&sourceOfFunds.provided.card.expiry.year=20&sourceOfFunds.provided.card.nameOnCard=John+Smith&sourceOfFunds.provided.card.number=4444333322221111&sourceOfFunds.provided.card.securityCode=123"

希望这能帮助处于类似情况的其他人。

编辑: 正如Drewg指出的,这不支持数组。要正确地实现对具有匿名类型的任意嵌套数组的支持是非常重要的,因为我使用的所有API都没有接受数组(我甚至不确定是否有标准化的方法用表单编码对它们进行序列化),如果需要支持的话,我将把它留给大家。

有一种将匿名对象转换为字典的内置方法:

HtmlHelper.AnonymousObjectToHtmlAttributes(yourObj)

它还会回来 RouteValueDictionary . 注意它是静态的

using Newtonsoft.Json;
var data = new {data1 = "test1", data2 = "sam", data3 = "bob"};
var encodedData = new FormUrlEncodedContent(JsonConvert.DeserializeObject<Dictionary<string, string>>(JsonConvert.SerializeObject(data))