使用Swashbuckle上传文件

Question

我有一个带有Swagger 3.0的ASP.NET Core2应用程序，我想测试一下从Swagger UI上传文件的POST操作。

文件上传器控制器：

[ApiController]
public class FileUploadController : ApiControllerBase
{
    private readonly IFileUploader _fileUploader;

    public FileUploadController(IFileUploader fileUploader, ILogger<FileUploadController> logger) : base(logger)
    {
        _fileUploader = fileUploader;
    }

    [HttpPost]
    [Route(nameof(UploadFile))]
    public FileUploadResult UploadFile(IFormFile uploadedFile)
    {
        return _FileUploader.UploadFile(Request.Form.Files[0]);
    }
}

阅读Swagger文档和其他主题时，我发现我需要自定义IOperationFilter，因此我想到了以下内容：

public class FileUploadOperationFilter : IOperationFilter
{
    public void Apply(Operation operation, OperationFilterContext context)
    {
        if (operation.OperationId.ToLower() == "apifileuploaduploadfilepost")
        {
            operation.Parameters.Add(new NonBodyParameter()
            {
                Name = "file",
                In = "formData",
                Description = "Upload File",
                Required = true,
                Type = "file"
            });
            operation.Consumes.Add("multipart/form-data");
        }
    }
}

它在Swagger启动类中注册：

                options.OperationFilter<FileUploadOperationFilter>();

所以，所有来自IFormFile的字段都消失了，并且有一个上传文件控件，所以我可以选择"Try it out“按钮，选择一个文件，但在按下"Execute”之后，我得到以下错误：

​

web api本身不会崩溃，也不会抛出任何错误。我在调试过程中注意到的是-- FileUploadController的构造函数已经到达，但是FileUpload方法没有被触发。

Answer 1

通过从参数中删除IFormFile uploadedFile来解决：

    [HttpPost]
[Route(nameof(UploadFile))]
public FileUploadResult UploadFile()
{
    return _FileUploader.UploadFile(Request.Form.Files[0]);
}

Answer 2

表单中的键应与方法中的参数匹配，请在筛选器中重命名：

operation.Parameters.Add(new NonBodyParameter()
            {
                Name = "uploadedFile",
                In = "formData",
                Description = "Upload File",
                Required = true,
                Type = "file"
            });

Answer 3

您能否尝试此操作筛选器：

/// <summary>
/// Filter to enable handling file upload in swagger
/// </summary>
public class FormFileSwaggerFilter : IOperationFilter
{
    private const string formDataMimeType = "multipart/form-data";
    private static readonly string[] formFilePropertyNames =
        typeof(IFormFile).GetTypeInfo().DeclaredProperties.Select(p => p.Name).ToArray();

    /// <summary>
    /// Applies the specified operation.
    /// </summary>
    /// <param name="operation">The operation.</param>
    /// <param name="context">The context.</param>
    public void Apply(Operation operation, OperationFilterContext context)
    {
        var parameters = operation.Parameters;
        if (parameters == null || parameters.Count == 0) return;

        var formFileParameterNames = new List<string>();
        var formFileSubParameterNames = new List<string>();

        ProcessActionParameters(context, ref formFileParameterNames, ref formFileSubParameterNames);

        if (!formFileParameterNames.Any()) return;

        var consumes = operation.Consumes;
        consumes.Clear();
        consumes.Add(formDataMimeType);

        ProcessParameters(ref parameters, formFileSubParameterNames);

        ProcessFormFileParameters(formFileParameterNames, ref parameters);
    }

    private static void ProcessFormFileParameters(List<string> formFileParameterNames, ref IList<IParameter> parameters)
    {
        foreach (var formFileParameter in formFileParameterNames)
        {
            parameters.Add(new NonBodyParameter()
            {
                Name = formFileParameter,
                Type = "file",
                In = "formData"
            });
        }
    }

    private static void ProcessActionParameters(OperationFilterContext context, ref List<string> formFileParameterNames,
        ref List<string> formFileSubParameterNames)
    {
        foreach (var actionParameter in context.ApiDescription.ActionDescriptor.Parameters)
        {
            var properties =
                actionParameter.ParameterType.GetProperties()
                    .Where(p => p.PropertyType == typeof(IFormFile))
                    .Select(p => p.Name)
                    .ToArray();

            if (properties.Length != 0)
            {
                formFileParameterNames.AddRange(properties);
                formFileSubParameterNames.AddRange(properties);
                continue;
            }

            if (actionParameter.ParameterType != typeof(IFormFile)) continue;
            formFileParameterNames.Add(actionParameter.Name);
        }
    }

    private static void ProcessParameters(ref IList<IParameter> parameters, List<string> formFileSubParameterNames)
    {
        foreach (var parameter in parameters.ToArray())
        {
            if (!(parameter is NonBodyParameter) || parameter.In != "formData") continue;

            if (formFileSubParameterNames.Any(p => parameter.Name.StartsWith(p + "."))
                || formFilePropertyNames.Contains(parameter.Name))
                parameters.Remove(parameter);
        }
    }
}