REST API模型绑定用于复杂模型+集合+ IFormFile

Question

我有一个应该作为复杂参数模型的动作。它应包含以下应与模型绑定的属性：

1. IFormFile（绑定已经完成）
2. 字符串属性（绑定已经完成）
3. 字典

我在绑定到UploadHeaders类的元数据集合时遇到问题。我尝试过的所有方法均无效。我尝试了FormUrlEncodedContent和StringContent（作为JSON）。有人可以指出正确的方向，除了IFormFile和字符串属性之外，如何还绑定集合？ FileMetadata对象是仅具有键和值属性的类的集合。两者都是公开的。

服务器端：

动作模型：

public class UploadHeaders
{
    public IFormFile File { get; set; }

    public IList<FileMetadata> Metadata { get; set; }

    public string Author { get; set; }

    public int AuthorId { get; set; }

    public UploadHeaders()
    {
        this.Metadata = new List<FileMetadata>();
    }
}

动作：

public async Task<ActionResult> Upload([FromForm] UploadHeaders uploadHeaders)
{ 
...
}

调用服务器端上载操作的客户端方法：

static UploadResponse Upload(string fileToUpload, string fileName)
    {
        var multipartFormDataContent = new MultipartFormDataContent();
        var fileContent = new ByteArrayContent(File.ReadAllBytes(fileToUpload));
        multipartFormDataContent.Add(fileContent, "file", fileName);
        multipartFormDataContent.Add(new StringContent("Author"), "Author");
        multipartFormDataContent.Add(new StringContent("13"), "AuthorId");

        var metadataStringContent = new FormUrlEncodedContent(
            new []
            {
                new KeyValuePair<string, string>("Metadata[0].Key", "key1"),
                new KeyValuePair<string, string>("Metadata[0].Value", "value1")
            }
        );

        multipartFormDataContent.Add(metadataStringContent, "meta");

        var response = httpClient.PostAsync(httpClient.BaseAddress + "Upload", multipartFormDataContent).Result;

        string stringResult = response.Content.ReadAsStringAsync().Result;
        UploadResponse uploadResponse = JsonConvert.DeserializeObject<UploadResponse>(stringResult);
        Console.WriteLine("{0} to {1}, result {2}", fileToUpload, fileName, uploadResponse.Id);
        return uploadResponse;
    }

Answer 1

为了绑定集合，您还应该将其值也传递为StringContent

var multipartFormDataContent = new MultipartFormDataContent();
var fileContent = new ByteArrayContent(File.ReadAllBytes(fileToUpload));
multipartFormDataContent.Add(fileContent, "file", fileName);
multipartFormDataContent.Add(new StringContent("Author"), "Author");
multipartFormDataContent.Add(new StringContent("13"), "AuthorId");

// parameter name should follow this template
// {collection_name}[{index}].{property}
multipartFormDataContent.Add(new StringContent("key1"), "Metadata[0].Key");
multipartFormDataContent.Add(new StringContent("value1"), "Metadata[0].Value");