dotnet core swagger filter 隱藏接口和顯示枚舉描述

dotnet core 2.2開發項目中，常會使用Swagger UI來生成在線Api文檔。

某些接口不想放到Swagger中可以這樣寫Filter：

    /// <summary> 
    /// 隱藏swagger接口特性標識
    /// </summary> 
    [System.AttributeUsage(System.AttributeTargets.Method | System.AttributeTargets.Class)]
    public partial class HiddenApiAttribute : System.Attribute { }

    /// <summary>
    /// 隱藏接口，不生成到swagger文檔展示
    /// </summary>
    public class HiddenApiFilter : IDocumentFilter
    {
        /// <summary>
        /// 過濾器
        /// </summary>
        /// <param name="swaggerDoc"></param>
        /// <param name="context"></param>

        public void Apply(SwaggerDocument swaggerDoc, DocumentFilterContext context)
        {
            foreach (ApiDescription apiDescription in context.ApiDescriptions)
            {
                if (apiDescription.TryGetMethodInfo(out MethodInfo method))
                {
                    if (method.ReflectedType.CustomAttributes.Any(t => t.AttributeType == typeof(HiddenApiAttribute))
                            || method.CustomAttributes.Any(t => t.AttributeType == typeof(HiddenApiAttribute)))
                    {
                        string key = "/" + apiDescription.RelativePath;
                        if (key.Contains("?"))
                        {
                            int idx = key.IndexOf("?", System.StringComparison.Ordinal);
                            key = key.Substring(0, idx);
                        }
                        swaggerDoc.Paths.Remove(key);
                    }
                }
            }
        }
    }

　　注意：他不能隱藏一個Controller中的某個Method，比如僅隱藏Post或Get方法，因爲它是對路由Paths.Remove

       Starts.cs中加入代碼：

c.DocumentFilter<HiddenApiFilter>();

　　Controller類或某個方法加入代碼：

 [HiddenApi]
 public class ValuesController : ControllerBase
 {
     ...
 }

　　顯示枚舉描述

    /// <summary>
    /// Add enum value descriptions to Swagger
    /// </summary>
    public class EnumDocumentFilter : IDocumentFilter
    {
        /// <inheritdoc />
        public void Apply(SwaggerDocument swaggerDoc, DocumentFilterContext context)
        {
            // add enum descriptions to result models
            foreach (var schemaDictionaryItem in swaggerDoc.Definitions)
            {
                var schema = schemaDictionaryItem.Value;
                foreach (var propertyDictionaryItem in schema.Properties)
                {
                    var property = propertyDictionaryItem.Value;
                    var propertyEnums = property.Enum;
                    if (propertyEnums != null && propertyEnums.Count > 0)
                    {
                        property.Description += DescribeEnum(propertyEnums);
                    }
                }
            }
        }

        private static string DescribeEnum(IEnumerable<object> enums)
        {
            var enumDescriptions = new List<string>();
            Type type = null;
            foreach (var enumOption in enums)
            {
                if (type == null) type = enumOption.GetType();
                enumDescriptions.Add($"{Convert.ChangeType(enumOption, type.GetEnumUnderlyingType())} = {Enum.GetName(type, enumOption)}，{GetDescription(type, enumOption)}");
            }

            return $"{Environment.NewLine}{string.Join(Environment.NewLine, enumDescriptions)}";
        }
        public static string GetDescription(Type t, object value)
        {
            foreach (MemberInfo mInfo in t.GetMembers())
            {
                if (mInfo.Name == t.GetEnumName(value))
                {
                    foreach (Attribute attr in Attribute.GetCustomAttributes(mInfo))
                    {
                        if (attr.GetType() == typeof(DescriptionAttribute))
                        {
                            return ((DescriptionAttribute)attr).Description;
                        }
                    }
                }
            }
            return string.Empty;
        }
    }

　　Starts.cs中加入代碼：

  c.DocumentFilter<EnumDocumentFilter>();

　　以上。