代码之家 › 专栏 › 技术社区 › waleed

无法使用[]对对象类型的表达式应用索引

.net c#

waleed · 技术社区 · 11 月前

我正在为.netwindows表单上的API工作,我从提供的网站复制了代码,发现了错误 say“无法对'object'类型的表达式应用[]索引”如何修复此问题这是我的代码

  RestClient restClient = new RestClient("https://api.wassenger.com");
  RestRequest restRequest = new RestRequest("/v1/files");
   restRequest.Method = Method.Post;
   restRequest.AddHeader("Token", "122eb0a65870e715a1de9ad06d11881b841e6db485bd387");
   restRequest.AddHeader("Content-Type", "multipart/form-data");
   restRequest.AddFile("file", "/path/to/image.jpg");

  var response = restClient.Execute(restRequest);
  var json = JsonConvert.DeserializeObject(response.Content);
 //error at line below (string)json[0]["id]
 var fileId = (string)json[0]["id"];

Console.WriteLine("File uploaded successfully with ID: {0}", fileId);

返回的响应如下

 [
 {
"id": "606f888ed01a7a65946c0701",
"format": "native",
"filename": "sample.jpg",
"size": 53697,
"mime": "image/jpeg",
"ext": "jpeg",
"kind": "image",
"sha2":   "305fc37036ffd53aec6d8c4512c0114fd38ac52f85d334e29647a21f0835c801",
"tags": [],
"status": "active",
"mode": "default",
"createdAt": "2021-05-08T22:49:50.954Z",
"expiresAt": "2021-09-06T22:49:50.949Z"
}
]

1 回复 | 直到 11 月前

Yong Shun 11 月前

假设您的响应是一个JSON数组,您应该将其反序列化为 List<T> 哪一个 T 是基于JSON定义的类。

您可以使用 Visual Studio 或 Json2Csharp 将JSON转换为类。

public class Root
{
    [JsonProperty("id")]
    public string Id { get; set; }

    [JsonProperty("format")]
    public string Format { get; set; }

    [JsonProperty("filename")]
    public string Filename { get; set; }

    [JsonProperty("size")]
    public int Size { get; set; }

    [JsonProperty("mime")]
    public string Mime { get; set; }

    [JsonProperty("ext")]
    public string Ext { get; set; }

    [JsonProperty("kind")]
    public string Kind { get; set; }

    [JsonProperty("sha2")]
    public string Sha2 { get; set; }

    [JsonProperty("tags")]
    public List<object> Tags { get; set; }

    [JsonProperty("status")]
    public string Status { get; set; }

    [JsonProperty("mode")]
    public string Mode { get; set; }

    [JsonProperty("createdAt")]
    public DateTime CreatedAt { get; set; }

    [JsonProperty("expiresAt")]
    public DateTime ExpiresAt { get; set; }
}

string fileId = String.Empty;

List<Root> list = JsonConvert.DeserializeObject<List<Root>>(myJsonResponse);

if (list != null && list.Count > 0)
{
    fileId = list[0].Id;
}

或者你可以与 JArray .

using Newtonsoft.Json.Linq;

string fileId = String.Empty;

var jArray = JArray.Parse(response.Content);
if (jArray != null && jArray.Count > 0)
{
    fileId = jArray[0]["id"].ToString();
    // Alternative methods    
    // fileId = jArray[0].Value<string>("id"));
    // fileId = jArray[0].SelectToken("id").ToString());
}

推荐文章

SpaceCowboy74 Mohammad Aghazadeh · 使用Fluent Validation比较数组中的值

5 月前