您的 json 字符串包含在方括号 ([]) 中，因此它被解释为数组而不是单个 RetrieveMultipleResponse 对象.因此，您需要将其反序列化为 RetrieveMultipleResponse 的类型集合，例如:

Your json string is wrapped within square brackets ([]), hence it is interpreted as array instead of single RetrieveMultipleResponse object. Therefore, you need to deserialize it to type collection of RetrieveMultipleResponse, for example :

var objResponse1 = 
    JsonConvert.DeserializeObject<List<RetrieveMultipleResponse>>(JsonStr);