回答編集履歴

見直しキャンペーン中

2023/08/13 12:45

投稿

TN8001

スコア10213

answer CHANGED Viewed

@@ -163,44 +163,6 @@
         public SingleOrArrayConverter(bool canWrite) : base(canWrite) { }
     }
-    public class SingleOrArrayConverterFactory : JsonConverterFactory
-    {
-        public bool CanWrite { get; }
-        public SingleOrArrayConverterFactory() : this(true) { }
-        public SingleOrArrayConverterFactory(bool canWrite) => CanWrite = canWrite;
-        public override bool CanConvert(Type typeToConvert)
-        {
-            var itemType = GetItemType(typeToConvert);
-            if (itemType == null) return false;
-            if (itemType != typeof(string) && typeof(IEnumerable).IsAssignableFrom(itemType)) return false;
-            return typeToConvert.GetConstructor(Type.EmptyTypes) != null && !typeToConvert.IsValueType;
-        }
-        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
-        {
-            var itemType = GetItemType(typeToConvert);
-            var converterType = typeof(SingleOrArrayConverter<,>).MakeGenericType(typeToConvert, itemType);
-            return (JsonConverter)Activator.CreateInstance(converterType, new object[] { CanWrite });
-        }
-        static Type GetItemType(Type type)
-        {
-            if (type.IsPrimitive || type.IsArray || type == typeof(string)) return null;
-            while (type != null)
-            {
-                if (type.IsGenericType)
-                {
-                    var genType = type.GetGenericTypeDefinition();
-                    if (genType == typeof(List<>)) return type.GetGenericArguments()[0];
-                }
-                type = type.BaseType;
-            }
-            return null;
-        }
-    }
     public class SingleOrArrayConverter<TCollection, TItem> : JsonConverter<TCollection> where TCollection : class, ICollection<TItem>, new()
     {
         public bool CanWrite { get; }

見直しキャンペーン中

2023/08/13 12:40

投稿

TN8001

スコア10213

answer CHANGED Viewed

@@ -84,4 +84,160 @@
         public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
     }
 }
+```
+---
+System.Text.Json版
+[c# - How to handle both a single item and an array for the same property using System.Text.Json? - Stack Overflow](https://stackoverflow.com/questions/59430728/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-system)
+```cs
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+namespace Questions320367
+{
+    class Program
+    {
+        static void Main()
+        {
+            var arrayJson = @"
+{
+  ""LoginList"": {
+    ""LoginItem"": [
+      {
+        ""ID"": ""TEST01""
+      },
+      {
+        ""ID"": ""TEST02""
+      }
+    ]
+  }
+}";
+            var result = JsonSerializer.Deserialize<Rootobject>(arrayJson);
+            List<Loginitem> loginItem = result.LoginList.LoginItem;
+            Console.WriteLine(loginItem.Count);
+            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
+            var singleJson = @"
+{
+  ""LoginList"": {
+    ""LoginItem"": {
+      ""ID"": ""TEST01""
+    }
+  }
+}";
+            result = JsonSerializer.Deserialize<Rootobject>(singleJson);
+            loginItem = result.LoginList.LoginItem;
+            Console.WriteLine(loginItem.Count);
+            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
+        }
+    }
+    public class Rootobject
+    {
+        public Loginlist LoginList { get; set; }
+    }
+    public class Loginlist
+    {
+        [JsonConverter(typeof(SingleOrArrayConverter<Loginitem>))]
+        public List<Loginitem> LoginItem { get; set; }
+    }
+    public class Loginitem
+    {
+        public string ID { get; set; }
+    }
+    // [c# - How to handle both a single item and an array for the same property using System.Text.Json? - Stack Overflow](https://stackoverflow.com/questions/59430728/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-system)
+    public class SingleOrArrayConverter<TItem> : SingleOrArrayConverter<List<TItem>, TItem>
+    {
+        public SingleOrArrayConverter() : this(true) { }
+        public SingleOrArrayConverter(bool canWrite) : base(canWrite) { }
+    }
+    public class SingleOrArrayConverterFactory : JsonConverterFactory
+    {
+        public bool CanWrite { get; }
+        public SingleOrArrayConverterFactory() : this(true) { }
+        public SingleOrArrayConverterFactory(bool canWrite) => CanWrite = canWrite;
+        public override bool CanConvert(Type typeToConvert)
+        {
+            var itemType = GetItemType(typeToConvert);
+            if (itemType == null) return false;
+            if (itemType != typeof(string) && typeof(IEnumerable).IsAssignableFrom(itemType)) return false;
+            return typeToConvert.GetConstructor(Type.EmptyTypes) != null && !typeToConvert.IsValueType;
+        }
+        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+        {
+            var itemType = GetItemType(typeToConvert);
+            var converterType = typeof(SingleOrArrayConverter<,>).MakeGenericType(typeToConvert, itemType);
+            return (JsonConverter)Activator.CreateInstance(converterType, new object[] { CanWrite });
+        }
+        static Type GetItemType(Type type)
+        {
+            if (type.IsPrimitive || type.IsArray || type == typeof(string)) return null;
+            while (type != null)
+            {
+                if (type.IsGenericType)
+                {
+                    var genType = type.GetGenericTypeDefinition();
+                    if (genType == typeof(List<>)) return type.GetGenericArguments()[0];
+                }
+                type = type.BaseType;
+            }
+            return null;
+        }
+    }
+    public class SingleOrArrayConverter<TCollection, TItem> : JsonConverter<TCollection> where TCollection : class, ICollection<TItem>, new()
+    {
+        public bool CanWrite { get; }
+        public SingleOrArrayConverter() : this(true) { }
+        public SingleOrArrayConverter(bool canWrite) => CanWrite = canWrite;
+        public override TCollection Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            switch (reader.TokenType)
+            {
+                case JsonTokenType.Null: return null;
+                case JsonTokenType.StartArray:
+                    var list = new TCollection();
+                    while (reader.Read())
+                    {
+                        if (reader.TokenType == JsonTokenType.EndArray) break;
+                        list.Add(JsonSerializer.Deserialize<TItem>(ref reader, options));
+                    }
+                    return list;
+                default:
+                    return new TCollection { JsonSerializer.Deserialize<TItem>(ref reader, options) };
+            }
+        }
+        public override void Write(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options)
+        {
+            if (CanWrite && value.Count == 1)
+            {
+                JsonSerializer.Serialize(writer, value.First(), options);
+            }
+            else
+            {
+                writer.WriteStartArray();
+                foreach (var item in value) JsonSerializer.Serialize(writer, item, options);
+                writer.WriteEndArray();
+            }
+        }
+    }
+}
 ```

見直しキャンペーン中

2023/07/26 13:45

投稿

TN8001

スコア10213

answer CHANGED Viewed

@@ -1,87 +1,87 @@
-型が変わってしまったらただただ扱いづらいだけです。
-実際にやりたいことは、どちらを読んでも`List<Loginitem>`になることなんじゃないですか？
-[sendgrid - How to handle both a single item and an array for the same property using JSON.net - Stack Overflow](https://stackoverflow.com/questions/18994685/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-json-n/18997172#18997172)
-```C#
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
-using System;
-using System.Linq;
-using System.Collections.Generic;
-namespace Questions320367
-{
-    class Program
-    {
-        static void Main()
-        {
-            var arrayJson = @"
-{
-  ""LoginList"": {
-    ""LoginItem"": [
-      {
-        ""ID"": ""TEST01""
-      },
-      {
-        ""ID"": ""TEST02""
-      }
-    ]
-  }
-}";
-            var result = JsonConvert.DeserializeObject<Rootobject>(arrayJson);
-            List<Loginitem> loginItem = result.LoginList.LoginItem;
-            Console.WriteLine(loginItem.Count);
-            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
-            var singleJson = @"
-{
-  ""LoginList"": {
-    ""LoginItem"": {
-      ""ID"": ""TEST01""
-    }
-  }
-}";
-            result = JsonConvert.DeserializeObject<Rootobject>(singleJson);
-            loginItem = result.LoginList.LoginItem;
-            Console.WriteLine(loginItem.Count);
-            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
-        }
-    }
-    public class Rootobject
-    {
-        public Loginlist LoginList { get; set; }
-    }
-    public class Loginlist
-    {
-        [JsonConverter(typeof(SingleOrArrayConverter<Loginitem>))]
-        public List<Loginitem> LoginItem { get; set; }
-    }
-    public class Loginitem
-    {
-        public string ID { get; set; }
-    }
-    // [sendgrid - How to handle both a single item and an array for the same property using JSON.net - Stack Overflow](https://stackoverflow.com/questions/18994685/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-json-n/18997172#18997172)
-    internal class SingleOrArrayConverter<T> : JsonConverter
-    {
-        public override bool CanConvert(Type objectType) => objectType == typeof(List<T>);
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
-        {
-            var token = JToken.Load(reader);
-            if (token.Type == JTokenType.Array)
-            {
-                return token.ToObject<List<T>>();
-            }
-            return new List<T> { token.ToObject<T>() };
-        }
-        public override bool CanWrite => false;
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
-    }
-}
+型が変わってしまったら、ただただ扱いづらいだけです。
+実際にやりたいことは、どちらを読んでも`List<Loginitem>`になることではないですか？
+[sendgrid - How to handle both a single item and an array for the same property using JSON.net - Stack Overflow](https://stackoverflow.com/questions/18994685/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-json-n/18997172#18997172)
+```cs
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+using System;
+using System.Linq;
+using System.Collections.Generic;
+namespace Questions320367
+{
+    class Program
+    {
+        static void Main()
+        {
+            var arrayJson = @"
+{
+  ""LoginList"": {
+    ""LoginItem"": [
+      {
+        ""ID"": ""TEST01""
+      },
+      {
+        ""ID"": ""TEST02""
+      }
+    ]
+  }
+}";
+            var result = JsonConvert.DeserializeObject<Rootobject>(arrayJson);
+            List<Loginitem> loginItem = result.LoginList.LoginItem;
+            Console.WriteLine(loginItem.Count);
+            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
+            var singleJson = @"
+{
+  ""LoginList"": {
+    ""LoginItem"": {
+      ""ID"": ""TEST01""
+    }
+  }
+}";
+            result = JsonConvert.DeserializeObject<Rootobject>(singleJson);
+            loginItem = result.LoginList.LoginItem;
+            Console.WriteLine(loginItem.Count);
+            Console.WriteLine(string.Join(", ", loginItem.Select(x => x.ID)));
+        }
+    }
+    public class Rootobject
+    {
+        public Loginlist LoginList { get; set; }
+    }
+    public class Loginlist
+    {
+        [JsonConverter(typeof(SingleOrArrayConverter<Loginitem>))]
+        public List<Loginitem> LoginItem { get; set; }
+    }
+    public class Loginitem
+    {
+        public string ID { get; set; }
+    }
+    // [sendgrid - How to handle both a single item and an array for the same property using JSON.net - Stack Overflow](https://stackoverflow.com/questions/18994685/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-json-n/18997172#18997172)
+    internal class SingleOrArrayConverter<T> : JsonConverter
+    {
+        public override bool CanConvert(Type objectType) => objectType == typeof(List<T>);
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            var token = JToken.Load(reader);
+            if (token.Type == JTokenType.Array)
+            {
+                return token.ToObject<List<T>>();
+            }
+            return new List<T> { token.ToObject<T>() };
+        }
+        public override bool CanWrite => false;
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
+    }
+}
 ```

文修正

2021/02/04 09:28

投稿

TN8001

スコア10213

answer CHANGED Viewed

@@ -1,4 +1,5 @@
+型が変わってしまったらただただ扱いづらいだけです。
-型が変わってしまったらただただ扱いづらいだけですから、実際にやりたいことはどちらを読んでも`List<Loginitem>`になることなんじゃないですか？
+実際にやりたいことは、どちらを読んでも`List<Loginitem>`になることなんじゃないですか？
 [sendgrid - How to handle both a single item and an array for the same property using JSON.net - Stack Overflow](https://stackoverflow.com/questions/18994685/how-to-handle-both-a-single-item-and-an-array-for-the-same-property-using-json-n/18997172#18997172)