如何解决：'将Face API添加到项目失败'

Question

我正在尝试将Face API连接的服务添加到C＃Web应用程序，但是当该服务是“正在创建新的Face API ...”时，我收到错误消息：将Face API添加到项目失败：“属性”字段为无效，错误：“将值{null}转换为类型“ System.Boolean”时出错。路径“ isMigrated”。”

我已经更新了.NET和vs 2017的版本。创建新项目的过程并不顺利。当前项目是一个全新的项目，没有任何更改。我正在使用试用版Azure帐户。问题似乎与Face API的实现有关，因为到目前为止，“ isMigrated”在我的代码中还没有出现。

Answer 1

[遵循此official guide时，我得到的错误与您的错误相同。我不确定vs中的组件是否有问题，也许像是bug。

我对此进行了一些研究，发现所有已连接的服务都是在您的订阅中创建Face API服务，并将API密钥和端点写入您的Web应用程序appsettings.json文件中。实际上，我们可以手动完成此过程。

这些是让我自己进行演示的步骤：

1. 转到Azure portal，创建Face API认知服务

创建服务后，请在此处复制其键和端点：

2. 在VS中创建.net核心Web应用，在appsettings.json，其内容如下：

    {
      "Logging": {
        "LogLevel": {
          "Default": "Information",
          "Microsoft": "Warning",
          "Microsoft.Hosting.Lifetime": "Information"
        }
      },
      "AllowedHosts": "*",
      "FaceAPI_ServiceKey": "<key in previous step>",
      "FaceAPI_ServiceEndPoint": "<endpoint in previous step>"
    }

用以下代码替换startup.cs中的内容：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

using System.IO;
using System.Text;
using System.Net.Http;
using System.Net.Http.Headers;

namespace <your name space here>
{
    public class Startup
    {
        private IConfiguration configuration;

        public Startup(IConfiguration configuration)
        {
            this.configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddRazorPages();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, Microsoft.AspNetCore.Hosting.IHostingEnvironment env)
        {
            // TODO: Change this to your image's path on your site.
            string imagePath = @"images/face1.jpg";

            // Enable static files such as image files.
            app.UseStaticFiles();

            string faceApiKey = this.configuration["FaceAPI_ServiceKey"];
            string faceApiEndPoint = this.configuration["FaceAPI_ServiceEndPoint"];

            HttpClient client = new HttpClient();

            // Request headers.
            client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", faceApiKey);

            // Request parameters. A third optional parameter is "details".
            string requestParameters = "returnFaceId=true&returnFaceLandmarks=false&returnFaceAttributes=age,gender,headPose,smile,facialHair,glasses,emotion,hair,makeup,occlusion,accessories,blur,exposure,noise";

            // Assemble the URI for the REST API Call.
            string uri = faceApiEndPoint + "/detect?" + requestParameters;

            // Request body. Posts an image you've added to your site's images folder.
            var fileInfo = env.WebRootFileProvider.GetFileInfo(imagePath);
            var byteData = GetImageAsByteArray(fileInfo.PhysicalPath);

            string contentStringFace = string.Empty;
            using (ByteArrayContent content = new ByteArrayContent(byteData))
            {
                // This example uses content type "application/octet-stream".
                // The other content types you can use are "application/json" and "multipart/form-data".
                content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");

                // Execute the REST API call.
                var response = client.PostAsync(uri, content).Result;

                // Get the JSON response.
                contentStringFace = response.Content.ReadAsStringAsync().Result;
            }

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }


            /// <summary>
            /// Returns the contents of the specified file as a byte array.
            /// </summary>
            /// <param name="imageFilePath">The image file to read.</param>
            /// <returns>The byte array of the image data.</returns>
            static byte[] GetImageAsByteArray(string imageFilePath)
            {
                FileStream fileStream = new FileStream(imageFilePath, FileMode.Open, FileAccess.Read);
                BinaryReader binaryReader = new BinaryReader(fileStream);
                return binaryReader.ReadBytes((int)fileStream.Length);
            }

            /// <summary>
            /// Formats the given JSON string by adding line breaks and indents.
            /// </summary>
            /// <param name="json">The raw JSON string to format.</param>
            /// <returns>The formatted JSON string.</returns>
            static string JsonPrettyPrint(string json)
            {
                if (string.IsNullOrEmpty(json))
                    return string.Empty;

                json = json.Replace(Environment.NewLine, "").Replace("\t", "");

                string INDENT_STRING = "    ";
                var indent = 0;
                var quoted = false;
                var sb = new StringBuilder();
                for (var i = 0; i < json.Length; i++)
                {
                    var ch = json[i];
                    switch (ch)
                    {
                        case '{':
                        case '[':
                            sb.Append(ch);
                            if (!quoted)
                            {
                                sb.AppendLine();
                            }
                            break;
                        case '}':
                        case ']':
                            if (!quoted)
                            {
                                sb.AppendLine();
                            }
                            sb.Append(ch);
                            break;
                        case '"':
                            sb.Append(ch);
                            bool escaped = false;
                            var index = i;
                            while (index > 0 && json[--index] == '\\')
                                escaped = !escaped;
                            if (!escaped)
                                quoted = !quoted;
                            break;
                        case ',':
                            sb.Append(ch);
                            if (!quoted)
                            {
                                sb.AppendLine();
                            }
                            break;
                        case ':':
                            sb.Append(ch);
                            if (!quoted)
                                sb.Append(" ");
                            break;
                        default:
                            sb.Append(ch);
                            break;
                    }
                }
                return sb.ToString();
            }

            app.Run(async (context) =>
            {
                await context.Response.WriteAsync($"<p><b>Face Image:</b></p>");
                await context.Response.WriteAsync($"<div><img src=\"" + imagePath + "\" /></div>");
                await context.Response.WriteAsync($"<p><b>Face detection API results:</b></p>");
                await context.Response.WriteAsync("<p>");
                await context.Response.WriteAsync(JsonPrettyPrint(contentStringFace));
                await context.Response.WriteAsync("<p>");
            });

        }
    }
}

在wwwroot下添加一个文件夹并在此处放置图片，在这种情况下，图片名称为face1.jpg：

完成这些步骤后，运行项目，您可以看到它正常运行，如官方演示所示：

如果此帖子有帮助，请单击该答案左侧的灰色大选中按钮以标记此答案，以便对有相同问题的其他人有所帮助：）