无法将当前 JSON 数组（例如 [1,2,3]）反序列化为“TenantManagementWebApi.Entities.Tenant”类型

Question

我有以下错误：

JsonSerializationException: 无法反序列化当前 JSON 数组 （例如[1,2,3]）输入'TenantManagementWebApi.Entities.Tenant' 因为该类型需要一个 JSON 对象（例如 {"name":"value"}）来 正确反序列化。

要修复此错误，请将 JSON 更改为 JSON 对象（例如 {"name":"value"}）或将反序列化类型更改为数组或 实现集合接口的类型（例如ICollection, IList） 像 List<T> 这样可以从 JSON 数组反序列化。 JsonArrayAttribute 也可以添加到类型中以强制它 从 JSON 数组反序列化。 路径''，第 1 行，位置 1。

我的 web api 是这样的：

public class TenantModelBinder : IModelBinder
{
    public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
    {
        if (bindingContext.ModelType != typeof(Tenant))
        {
            return false;
        }

        var task = Task.Run(async () =>
        {
            var model = new Tenant();

            if (!actionContext.Request.Content.IsMimeMultipartContent())
            {
                bindingContext.ModelState.AddModelError(bindingContext.ModelName, "WebRequeest content 'multipart/form-data' is valid");
            }
            else
            {
                var provider = await actionContext.Request.Content.ReadAsMultipartAsync();

                //var fileContent = provider.Contents.FirstOrDefault(n => n.Headers.ContentDisposition.Name.Equals("file"));
                var fileContent = provider.Contents.FirstOrDefault(n => n.Headers.ContentDisposition.Name.Equals(@"""file"""));
                if (fileContent == null)
                {
                    bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Section 'file' is missed");
                }

                //var modelContent = provider.Contents.FirstOrDefault(n => n.Headers.ContentDisposition.Name.Equals("model"));
                var modelContent = provider.Contents.FirstOrDefault(n => n.Headers.ContentDisposition.Name.Equals(@"""model"""));
                if (modelContent == null)
                {
                    bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Section 'model' is missed");
                }

                if (fileContent != null && modelContent != null)
                {
                    model = JsonConvert.DeserializeObject<Tenant>(await modelContent.ReadAsStringAsync());
                    //model.Text = "<NativeTranslation>";
                    model.ContentType = provider.Contents[0].Headers.ContentType.MediaType;
                    model.CertificateFile = await fileContent.ReadAsByteArrayAsync();
                    //model.TenantId = fileContent.Headers.ContentDisposition.FileName;
                }
            }

            return model;
        });

        task.Wait();

        bindingContext.Model = task.Result;
        return true;
    }
}

[HttpPut]
public async Task<IHttpActionResult> PutTenant([ModelBinder(typeof(TenantModelBinder))] Tenant tenant)
{
    //var provider = new MultipartMemoryStreamProvider();
    //var contentType = "";
    //var content = new byte[0];
    //await base.Request.Content.ReadAsMultipartAsync(provider);
    //if (provider.Contents.Count > 0)
    //{
    //    contentType = provider.Contents[0].Headers.ContentType.MediaType;
    //    content = await provider.Contents[0].ReadAsByteArrayAsync();
    //}


    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConfigurationManager.AppSettings["AzureStorageKey"].ToString());
    // Create the blob client.
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

    // Retrieve reference to a previously created container.
    CloudBlobContainer container = blobClient.GetContainerReference(ConfigurationManager.AppSettings["certificatesContainer"].ToString());

    // Retrieve reference to a blob named "myblob".
    CloudBlockBlob blockBlob = container.GetBlockBlobReference("myblob");

    // Create or overwrite the "myblob" blob with contents from a local file.
    blockBlob.Properties.ContentType = tenant.ContentType;
    MemoryStream stream = new MemoryStream(tenant.CertificateFile);
    blockBlob.UploadFromStream(stream);

    var tenantStore = CosmosStoreFactory.CreateForEntity<Tenant>();
    tenant.CertificatePath = blockBlob.Uri;

    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }

    var added = await tenantStore.AddAsync(tenant);
    return StatusCode(HttpStatusCode.NoContent); 
}

public class Tenant
{
    public string TenantId { get; set; }
    public string TenantUrl { get; set; }
    public Uri CertificatePath { get; set; }
    public string CertificatePassword { get; set; }

    public byte[] CertificateFile { get; set; }
    public string ContentType { get; set; }

    public override string ToString()
    {
        return JsonConvert.SerializeObject(this);
    }
}

还有我的 React 组件

import React, { Component } from 'react';
import { Row, Col } from 'antd';
import PageHeader from '../../components/utility/pageHeader';
import Box from '../../components/utility/box';
import LayoutWrapper from '../../components/utility/layoutWrapper.js';
import ContentHolder from '../../components/utility/contentHolder';
import basicStyle from '../../settings/basicStyle';
import IntlMessages from '../../components/utility/intlMessages';
import { adalApiFetch } from '../../adalConfig';

export default class extends Component {
  constructor(props) {
    super(props);
    this.state = {TenantId: '', TenantUrl: '', TenantPassword: '' };
    this.handleChangeTenantUrl = this.handleChangeTenantUrl.bind(this);
    this.handleChangeTenantPassword = this.handleChangeTenantPassword.bind(this);
    this.handleChangeTenantId= this.handleChangeTenantId.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  };


  handleChangeTenantUrl(event){
    this.setState({TenantUrl: event.target.value});
  }

  handleChangeTenantPassword(event){
    this.setState({TenantPassword: event.target.value});
  }

  handleChangeTenantId(event){
    this.setState({TenantId: event.target.value});
  }

  handleSubmit(event){
    event.preventDefault();

    let data = new FormData();
    //Append files to form data
    data.append("model", {"TenantId": this.state.TenantId, "TenantUrl": this.state.TenantUrl, "TenantPassword": this.state.TenantPassword });

    let files = this.state.selectedFiles;
    for (let i = 0; i < files.length; i++) {
      data.append("file", files[i], files[i].name);
    }

    const options = {
      method: 'put',
      body: data,
      config: {
        headers: {
          'Content-Type': 'multipart/form-data'
        }
      }
    };

    adalApiFetch(fetch, "/Tenant", options)
      .then(response => response.json())
      .then(responseJson => {
        if (!this.isCancelled) {
          this.setState({ data: responseJson });
        }
      })
      .catch(error => {
        console.error(error);
      });
  }


  upload(e){
    let files = e.target.files;
    this.setState({ 'selectedFiles': files });
}

  render(){
    const { data } = this.state;
    const { rowStyle, colStyle, gutter } = basicStyle;

    return (
      <div>
        <LayoutWrapper>
        <PageHeader>{<IntlMessages id="pageTitles.TenantAdministration" />}</PageHeader>
        <Row style={rowStyle} gutter={gutter} justify="start">
          <Col md={12} sm={12} xs={24} style={colStyle}>
            <Box
              title={<IntlMessages id="pageTitles.TenantAdministration" />}
              subtitle={<IntlMessages id="pageTitles.TenantAdministration" />}
            >
              <ContentHolder>
              <form onSubmit={this.handleSubmit}>
                <label>
                  TenantId:
                  <input type="text" value={this.state.TenantId} onChange={this.handleChangeTenantId} />
                </label>
                <label>
                  TenantUrl:
                  <input type="text" value={this.state.TenantUrl} onChange={this.handleChangeTenantUrl} />
                </label>
                <label>
                  TenantPassword:
                  <input type="text" value={this.state.TenantPassword} onChange={this.handleChangeTenantPassword} />
                </label>
                <label>
                  Certificate:
                  <input onChange = { e => this.upload(e) } type = "file" id = "files" ref = { file => this.fileUpload } />
                </label>            
              <input type="submit" value="Submit" />
              </form>
              </ContentHolder>
            </Box>
          </Col>
        </Row>
      </LayoutWrapper>
      </div>
    );
  }
}

引发错误的行是这样的：

model = JsonConvert.DeserializeObject<Tenant>(await modelContent.ReadAsStringAsync());

Answer 1

您的model 以string 表示形式发布，而不是JSON。
await modelContent.ReadAsStringAsync() 将返回数组表示法中的字符串：[object Object]。

您必须自己处理 JSON 序列化。

替换

data.append("model", { "TenantId": this.state.TenantId, "TenantUrl": this.state.TenantUrl, "TenantPassword": this.state.TenantPassword });

与

data.append("model", JSON.stringify({ "TenantId": this.state.TenantId, "TenantUrl": this.state.TenantUrl, "TenantPassword": this.state.TenantPassword }));