Question

我有一个用ASP.NET Core Web API 2.1编写的文档服务API。该API当前接受包含1个文件信息的ViewModel，然后将该文件和信息保存到服务器。我想添加添加多个文件的功能，但是当作为集合的一部分上载时，无法绑定IFormFile文件。

/// The ViewModel being uploaded.
public class FileUploadDto
{
    public Guid Id { get; set; }
    public string Description { get; set; }
    public string Name { get; set; }
    public IFormFile File { get; set; }
}

/// Works perfect. All properties are bound to the fileUploadRequest object.
[HttpPost]
public async Task<IActionResult> Add(FileUploadDto fileUploadRequest)
{
    /// Process

    return Ok();
}

/// All properties are bound to the objects in the collection, except for the File property.
[HttpPost]
public async Task<IActionResult> AddRange([FromForm] IEnumerable<FileUploadDto> fileUploadRequests)
{
    foreach (FileUploadDto fileUploadRequest in fileUploadRequests)
    {
        //fileUploadRequest.File is null
    }

    return Ok();
}

我正在使用邮递员对此进行测试，并使用表单数据将正文中的内容上传为：

[0] [说明]：测试（类型：文本）
[0] [名称]：测试（类型：文本）
[0] [文件]：sample.txt（类型：文件）

multipart/form-data在内容类型标题中设置。

更新：
通过执行以下操作，我找到了一种解决方法，但是显然这不是最好的方法。我认识到问题在于文件没有绑定到我的ViewModels，而是存储在Request.Form.Files集合中。不过，我不确定该如何解决。

[HttpPost]
public async Task<IActionResult> AddRange([FromForm] IEnumerable<FileUploadDto> fileUploadRequests)
{
    var index = 0;
    foreach (FileUploadDto fileUploadRequest in fileUploadRequests)
    {
        //fileUploadRequest.File is null
        fileUploadRequest.File = Request.Form.Files[index];
        index += 1;
    }

    return Ok();
}

Answer 1

我最终传递了一个附加属性，以指定要在请求表中使用的文件索引。

/// The ViewModel being uploaded.
public class FileUploadDto
{
    public Guid Id { get; set; }
    public string Description { get; set; }
    public string Name { get; set; }
    public int? FileIndex { get; set; }
    public IFormFile File { get; set; }
}

/// Works perfect. All properties are bound to the fileUploadRequest object.
[HttpPost]
public async Task<IActionResult> Add(FileUploadDto fileUploadRequest)
{
    /// Process

    return Ok();
}

/// All properties are bound to the objects in the collection, except for the File property.
[HttpPost]
public async Task<IActionResult> AddRange([FromForm] IEnumerable<FileUploadDto> fileUploadRequests)
{
    foreach (FileUploadDto fileUploadRequest in fileUploadRequests)
    {
        fileUploadRequest.File = Request.Form.Files[fileUploadRequest.FileIndex ?? -1];
    }

    return Ok();
}

在Asp.Net Core 2.1中上载包含IFormFile的ViewModel的集合

1 个答案: