Netcore webapi action swagger response返回参数使用匿名类型

问题：action中返回匿名对象时，swagger只能按强类型生成返回值描述

解决办法：使用roslyn在内存中动态执行代码，使用json.net反序列化匿名对象，向swagger返回动态匿名对象

效果：

Swaager在描述控制器的方法时，可以使用以下方法

<response code="400">如果id为空</response>

或

[ProducesResponseType(typeof(ResponseT<User>),
200)]

Openapi json如下

生成效果如下图

上述方法必须存在强类型user

代码

@@@code
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public class AnonymousTypeProducesResponseTypeAttribute : Microsoft.AspNetCore.Mvc.ProducesResponseTypeAttribute
{
public AnonymousTypeProducesResponseTypeAttribute(string typeJson, int statusCode) : base(getAnonymousType(typeJson), statusCode)
{
}
/// <summary>
///
/// </summary>
/// <param name="typeJson">匿名类型描述串
/// </param>
/// <example>new {id=1,name=""}</example>
/// <param name="statusCode"></param>
static System.Type getAnonymousType(string typeJson)
{
var code = @"
public class Result {
public System.Type GetType2(){
var t = Newtonsoft.Json.JsonConvert.DeserializeAnonymousType(""{}"", #T#);
return t.GetType();
}
}
".Replace("#T#", typeJson.Replace("'", @""""));
 
 List<PortableExecutableReference> refList = new List<PortableExecutableReference>();
refList.Add(MetadataReference.CreateFromFile(typeof(object).Assembly.Location));
refList.Add(MetadataReference.CreateFromFile(typeof(Newtonsoft.Json.JsonConvert).Assembly.Location));
refList.Add(MetadataReference.CreateFromFile(typeof(System.Runtime.AssemblyTargetedPatchBandAttribute).Assembly.Location));
refList.Add(MetadataReference.CreateFromFile(System.IO.Path.Combine(System.IO.Path.GetDirectoryName(typeof(object).Assembly.Location), "netstandard.dll")));
 
 var tree = CSharpSyntaxTree.ParseText(code);
var compilation = CSharpCompilation.Create("test")
.WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary))
.AddReferences(refList.ToArray()).AddSyntaxTrees(tree);
using (var stream = new MemoryStream())
{
var emitResult = compilation.Emit(stream);
if (emitResult.Success)
{
stream.Seek(0, SeekOrigin.Begin);
var assembly = Assembly.Load(stream.ToArray());
var typeResult = assembly.GetType("Result");
var m = Activator.CreateInstance(typeResult);
var Type = m.GetType();
return typeResult.GetMethod("GetType2").Invoke(m, null) as Type;
}
}
 
 return null;
}
}
@@#

使用

@@@code
[HttpGet("Dept/Get")]
[AnonymousTypeProducesResponseType(@"new {Code=0,Msg='',Data=new []{new {id=0,name=''}}}", 200)]
public object DeptGet()
{
return new
{
Code = 0,
Msg = string.Empty,
Data = _context. Group.Select(r => new
{
id = r. ID,
name = r. Name
}).ToList()
};
}
@@#

另一种借助元组实现的方法

花了大量时间获取属性名没有结果，泛型传递时的方法获取 不到TupleElementNamesAttribute，只能走动态方法获取 返回值 ，再利用TupleElementNamesAttribute获取 名称

@@@code
public class ResponseT<T>
{
//有效 [JsonProperty("haaa")]
public int Code { get; set; }
// 无效 [JsonConverter(typeof(Q.DevExtreme.Tpl.Json.IPAddressConverter))]
public string Msg { get; set; }
public T Data { get; set; }
 
 public T[] GetData()
{
//泛型，丢失名称信息，没有TupleElementNamesAttribute属性
		return new[] { Data };
}
public (int a, string b) GetData2()
{
//可以使用下列方法获得名称
//Type t = typeof(C);
//MethodInfo method = t.GetMethod(nameof(C.M));
//var attr = method.ReturnParameter.GetCustomAttribute<TupleElementNamesAttribute>();
 
 //string[] names = attr.TransformNames;
 
 return (1, "2");
}
}
@@#

使用

@@@code
[ProducesResponseType(typeof(ResponseT<(int id,string name)>), 400)]
@@E