How to add an object or key value pair to MultipartFormDataContent then send it and receive it on th-CodePudding

I am sending an image to the API using MultipartFormDataContent and i can grab the image using var file = HttpContext.Request.Form.Files; without a problem. How can I send additional data like an array or object together with the image and then grab it on the other end of the API? I tried using Key value pairs but with no luck getting it on the API. Below is how i am adding using key value pair but i have no idea how i can receive this data on the API:

using (var client = new HttpClient())
{
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
    using (var content = new MultipartFormDataContent())
    {
        var fileStream = new FileStream(tempFilePath, FileMode.Open);
        formData.Add(new StreamContent(fileStream), fileName, fileName);
        //Below am sending the name from the object lblobj and giving it a key of name
        formData.Add(new StringContent(lblobj.Name), "name");
        streams.Add(fileStream);

        var request = new HttpRequestMessage(HttpMethod.Post, new Uri(_configuration["Application:ApiEndPoint"])   "api/Label/Create")
        {
            Content = formData,
        };

        request.Headers.Add("accept", "application/json");

        var response = await client.SendAsync(request);
        streams.ForEach(stream =>
        {
            stream.Dispose();
        });

        if (response.IsSuccessStatusCode)
        {
            //Handle success
        }
        //handle failure

    }
}

Below is how i receive the file on the API:

 var image = HttpContext.Request.Form.Files;
//Deal with the image(iformfile)

How can i receive the additional data above?

CodePudding user response：

Here's my test result:

using Microsoft.AspNetCore.Hosting;

private readonly IHostingEnvironment _hostingEnvironment;

public HomeController( IHostingEnvironment hostingEnvironment)
{
    _hostingEnvironment = hostingEnvironment;
}

[HttpPost]
public async Task receiveDataAsync(ApiModel model) {
    var name = model.fileName;
    var file = model.image;
    if (file != null)
    {
        string uploadsPath = Path.Combine(_hostingEnvironment.WebRootPath, "css");
        string uniqueName = Guid.NewGuid().ToString()   "_"   name ".png";
        string filePath = Path.Combine(uploadsPath, uniqueName);
        using (Stream fileStream = new FileStream(filePath, FileMode.Create))
        {
            await file.CopyToAsync(fileStream);
        }
    }
}

And this is the model, and I also think you need to create a model for your api:

using Microsoft.AspNetCore.Http;

namespace WebMvcApp.Models
{
    public class ApiModel
    {
        public string fileName { get; set; }
        public IFormFile image { get; set; }
    }
}

CodePudding user response：

I appended the strings from my object in key value pairs like below

   formData.Add(new StringContent(lblobj.PageColor), "pageColor");
   formData.Add(new StringContent(lblobj.Name), "name");                       
   formData.Add(new StringContent(lblobj.SidebarColor), "sidebarColor");
   formData.Add(new StringContent(lblobj.SidebarLinkColor), "sidebarLinkColor");

On the API end point all i did was append these to a model containing all those keys like below;

 public IActionResult Create([FromForm] Label labelobj)
{

//Do something with the values }

The labelobj contains pageColor etc