Stand-alone implementation of Swashbuckle.AspNetCore pull #960 which fixes the formatting of non-string JSON examples. Can be used with existing distributions until the pull makes it into a public release. See https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/1021 for instructions.

XmlCommentsSchemaFilter_Fix960.cs

using System;
using System.ComponentModel;
using System.Xml.XPath;
using System.Reflection;
using System.Linq;
using Microsoft.OpenApi.Any;
using Newtonsoft.Json.Serialization;
using Microsoft.OpenApi.Models;
using Microsoft.AspNetCore.Mvc;

namespace Swashbuckle.AspNetCore.SwaggerGen
{
    internal static class JsonPropertyExtensions
    {
        internal static bool TryGetMemberInfo(this JsonProperty jsonProperty, out MemberInfo memberInfo)
        {
            if (jsonProperty.UnderlyingName == null)
            {
                memberInfo = null;
                return false;
            }

            var metadataAttribute = jsonProperty.DeclaringType.GetTypeInfo()
                .GetCustomAttributes(typeof(ModelMetadataTypeAttribute), true)
                .FirstOrDefault();

            var typeToReflect = (metadataAttribute != null)
                ? ((ModelMetadataTypeAttribute)metadataAttribute).MetadataType
                : jsonProperty.DeclaringType;

            memberInfo = typeToReflect.GetMember(jsonProperty.UnderlyingName).FirstOrDefault();

            return (memberInfo != null);
        }
    }

    /// <summary>
    /// Implementation of <see cref="XmlCommentsSchemaFilter"/> with https://github.com/domaindrivendev/Swashbuckle.AspNetCore/pull/960 applied,
    /// for use until the fix is put in a release of Swashbuckle.AspNetCore
    /// </summary>
    public class XmlCommentsSchemaFilter_Fix960 : ISchemaFilter
    {
        private const string MemberXPath = "/doc/members/member[@name='{0}']";
        private const string SummaryTag = "summary";
        private const string ExampleXPath = "example";

        private readonly XPathNavigator _xmlNavigator;

        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="xmlDoc"></param>
        public XmlCommentsSchemaFilter_Fix960(XPathDocument xmlDoc)
        {
            _xmlNavigator = xmlDoc.CreateNavigator();
        }

        /// <summary>
        /// Apply filter
        /// </summary>
        public void Apply(OpenApiSchema schema, SchemaFilterContext context)
        {
            var jsonObjectContract = context.JsonContract as JsonObjectContract;
            if (jsonObjectContract == null) return;

            var memberName = XmlCommentsMemberNameHelper.GetMemberNameForType(context.SystemType);
            var typeNode = _xmlNavigator.SelectSingleNode(string.Format(MemberXPath, memberName));

            if (typeNode != null)
            {
                var summaryNode = typeNode.SelectSingleNode(SummaryTag);
                if (summaryNode != null)
                    schema.Description = XmlCommentsTextHelper.Humanize(summaryNode.InnerXml);
            }

            if (schema.Properties == null) return;
            foreach (var entry in schema.Properties)
            {
                var jsonProperty = jsonObjectContract.Properties[entry.Key];
                if (jsonProperty == null) continue;

                if (jsonProperty.TryGetMemberInfo(out MemberInfo memberInfo))
                {
                    ApplyPropertyComments(entry.Value, memberInfo);
                }
            }
        }

        private void ApplyPropertyComments(OpenApiSchema propertySchema, MemberInfo memberInfo)
        {
            var memberName = XmlCommentsMemberNameHelper.GetMemberNameForMember(memberInfo);
            var memberNode = _xmlNavigator.SelectSingleNode(string.Format(MemberXPath, memberName));
            if (memberNode == null) return;

            var summaryNode = memberNode.SelectSingleNode(SummaryTag);
            if (summaryNode != null)
            {
                propertySchema.Description = XmlCommentsTextHelper.Humanize(summaryNode.InnerXml);
            }

            var exampleNode = memberNode.SelectSingleNode(ExampleXPath);
            if (exampleNode != null)
            {
                var exampleString = XmlCommentsTextHelper.Humanize(exampleNode.InnerXml);
                var memberType = (memberInfo.MemberType & MemberTypes.Field) != 0 ? ((FieldInfo)memberInfo).FieldType : ((PropertyInfo)memberInfo).PropertyType;
                propertySchema.Example = ConvertToOpenApiType(exampleString, memberType);
            }
        }

        private static IOpenApiPrimitive ConvertToOpenApiType(string value, Type type)
        {
            object typedExample;

            try
            {
                typedExample = TypeDescriptor.GetConverter(type).ConvertFrom(value);
            }
            catch (Exception)
            {
                return new OpenApiString(value);
            }

            return OpenApiPrimitiveFactory.CreateFrom(typedExample) ?? new OpenApiString(value);
        }
    }
}