c# – 创建一个新的AnonymousType实例

new { Channel = g.Key.Channel,Comment = g.Key.Comment,Count = g.Count() }

在黑暗中,.NET创建一个带有构造函数的AnonymousType,它带有三个参数：String,String,Int32.

为了创建这个匿名类型的新实例,我做：

object[] args = new object[3];
args[0] = "arg1";
args[1] = "arg2";
args[2] = 200;
(T)Activator.CreateInstance(typeof(T),args);

.NET转发我：

Additional information: Constructor not found in ‘<>f__AnonymousType2`3[[System.String,…],[System.String,[System.Int32,…]]’.

我不知道为什么CreateInstance试图调用像[[],[],[]]这样的构造函数！

范围

真正的范围有点难以解释：

我创建了一个Linq提供者.此提供程序将Linq语句翻译为我的服务器方法.当我收到json信息时,我需要将此信息投影到用户指定的类型.在这种情况下：

var enumerable = UIContainer.UIController.Instance.getDigitalInputs()
    .GroupBy(di => new { Channel = di.Channel,Comment = di.Comment })
    .Select(g => new { Channel = g.Key.Channel,Count = g.Count() });

所以,我需要将每个json项目投影到一个新的{Channel = g.Key.Channel,Count = g.Count()}).最后,我需要创建一个匿名类型的实例.

所以：

// make the HTTP request
IRestResponse response = (IRestResponse) this.client.CallApi(path,Method.GET,queryParams,postBody,headerParams,formParams,fileParams,authSettings);

if (((int)response.StatusCode) >= 400) {
    throw new ApiException (response.StatusCode,"Error calling Search: " + response.Content,response.Content);
}

Newtonsoft.Json.Linq.JArray feeds = Newtonsoft.Json.Linq.JArray.Parse(response.Content);
if (feeds.Any())
{
     PropertyDescriptorCollection dynamicProperties = TypeDescriptor.GetProperties(feeds.First());
     foreach (dynamic feed in feeds)
     {
         object[] args = new object[dynamicProperties.Count];
         int i = 0;
         foreach (PropertyDescriptor prop in dynamicProperties)
         {
             args[i++] = prop.GetValue(feed);
         }
         //args[0] = "";
         //args[1] = "";
         //args[2] = 2;

         yield return (T)Activator.CreateInstance(typeof(T),args);
    }
}