無法在JSON響應中從{null}轉換或轉換爲system.Int32 C＃

Question

使用此位代碼反序列化來自CrunchBase的JSON響應時，出現以下異常。奇怪的是，它只發生在正在被反序列化的某些頁面上，即使結果工作正常，並且在鍵值對中都沒有空[]，空「」和空值。我如何施放或糾正我的錯誤？

異常被拋出在這裏：

JsonSerializer serializer = new JsonSerializer(); 
    RootObject ro = JsonConvert.DeserializeObject<RootObject>(response); 

內部異常是：

InnerException: 
    Message=Could not cast or convert from {null} to System.Int32. 
    Source=Newtonsoft.Json 

感謝您的眼睛提前！

更新： 詢問該JSON端點上的根對象和其他對象的結構。在將JSON端點的URL放入其中之後，這些內容由http://json2csharp.com/生成。

的JSON是長，所以這裏有兩個例子鏈接：這個工作沒有錯誤http://api.crunchbase.com/v/1/company/kiip.js，而這個其他（及其他）拋出異常http://api.crunchbase.com/v/1/company/tata-communications.js

 public class Image 
    { 
     public List<List<object>> available_sizes { get; set; } 
     public object attribution { get; set; } 
    } 

    public class Person 
    { 
     public string first_name { get; set; } 
     public string last_name { get; set; } 
     public string permalink { get; set; } 
    } 

    public class Relationship 
    { 
     public bool is_past { get; set; } 
     public string title { get; set; } 
     public Person person { get; set; } 
    } 

    public class Provider 
    { 
     public string name { get; set; } 
     public string permalink { get; set; } 
    } 

    public class Providership 
    { 
     public string title { get; set; } 
     public bool is_past { get; set; } 
     public Provider provider { get; set; } 
    } 

    public class FinancialOrg 
    { 
     public string name { get; set; } 
     public string permalink { get; set; } 
    } 

    public class Person2 
    { 
     public string first_name { get; set; } 
     public string last_name { get; set; } 
     public string permalink { get; set; } 
    } 

    public class Investment 
    { 
     public object company { get; set; } 
     public FinancialOrg financial_org { get; set; } 
     public Person2 person { get; set; } 
    } 

    public class FundingRound 
    { 
     public string round_code { get; set; } 
     public string source_url { get; set; } 
     public string source_description { get; set; } 
     public double raised_amount { get; set; } 
     public string raised_currency_code { get; set; } 
     public int funded_year { get; set; } 
     public int funded_month { get; set; } 
     public int funded_day { get; set; } 
     public List<Investment> investments { get; set; } 
    } 

    public class Office 
    { 
     public string description { get; set; } 
     public string address1 { get; set; } 
     public string address2 { get; set; } 
     public string zip_code { get; set; } 
     public string city { get; set; } 
     public string state_code { get; set; } 
     public string country_code { get; set; } 
     public object latitude { get; set; } 
     public object longitude { get; set; } 
    } 

    public class VideoEmbed 
    { 
     public string embed_code { get; set; } 
     public string description { get; set; } 
    } 

    public class Screenshot 
    { 
     public List<List<object>> available_sizes { get; set; } 
     public object attribution { get; set; } 
    } 

    public class RootObject 
    { 
     public string name { get; set; } 
     public string permalink { get; set; } 
     public string crunchbase_url { get; set; } 
     public string homepage_url { get; set; } 
     public string blog_url { get; set; } 
     public string blog_feed_url { get; set; } 
     public string twitter_username { get; set; } 
     public string category_code { get; set; } 
     public int number_of_employees { get; set; } 
     public int founded_year { get; set; } 
     public int founded_month { get; set; } 
     public object founded_day { get; set; } 
     public object deadpooled_year { get; set; } 
     public object deadpooled_month { get; set; } 
     public object deadpooled_day { get; set; } 
     public object deadpooled_url { get; set; } 
     public string tag_list { get; set; } 
     public string alias_list { get; set; } 
     public string email_address { get; set; } 
     public string phone_number { get; set; } 
     public string description { get; set; } 
     public string created_at { get; set; } 
     public string updated_at { get; set; } 
     public string overview { get; set; } 
     public Image image { get; set; } 
     public List<object> products { get; set; } 
     public List<Relationship> relationships { get; set; } 
     public List<object> competitions { get; set; } 
     public List<Providership> providerships { get; set; } 
     public string total_money_raised { get; set; } 
     public List<FundingRound> funding_rounds { get; set; } 
     public List<object> investments { get; set; } 
     public object acquisition { get; set; } 
     public List<object> acquisitions { get; set; } 
     public List<Office> offices { get; set; } 
     public List<object> milestones { get; set; } 
     public object ipo { get; set; } 
     public List<VideoEmbed> video_embeds { get; set; } 
     public List<Screenshot> screenshots { get; set; } 
     public List<object> external_links { get; set; } 
    } 

Answer 1

Json.NET支持JSON Schema。您可以創建一個具有所有必需屬性的模式，並在反序列化之前驗證傳入的JSON。在這裏你可以檢查是否值是null你可以改變它爲某個默認值。

希望這對你有用。