[英]Convert JObject to multi-dimensional array
如何將JObject轉換為3D數組? 我有一個這樣格式化的JObject:
{
"0": [
[
1.0,
2.0,
3.0
],
[
4.0,
5.0,
6.0
]
],
"1": [
[
7.0,
8.0,
9.0
],
[
10.0,
11.0,
12.0
]
]
}
我嘗試將其強制轉換為double[,,]
但失敗並顯示錯誤
Unable to cast object of type 'Newtonsoft.Json.Linq.JObject' to type 'System.Double[,,]'.
以下對我有用:
var deserailizationExp = JsonConvert.DeserializeObject<Dictionary<string, double[,]>>(@"
{""0"": [
[
1.0,
2.0,
3.0
],
[
4.0,
5.0,
6.0
]
],
""1"": [
[
7.0,
8.0,
9.0
],
[
10.0,
11.0,
12.0
]
]
}");
然后,您可以直接使用字典,也可以將其轉換為數組。 編輯:正如對此評論中所指出的那樣,您也可以考慮將其反序列化為SortedDictionary<int, double[,]>
。 我將其作為一種類型進行了測試,並且對我有用。
另外,如果您修改JSON,則可以執行以下操作:
var otherDes = JsonConvert.DeserializeObject<double[,,]>(@"
[[
[
1.0,
2.0,
3.0
],
[
4.0,
5.0,
6.0
]
],
[
[
7.0,
8.0,
9.0
],
[
10.0,
11.0,
12.0
]
]
]");
如您所見,我剛剛刪除了“ 0”和“ 1”,並將{}替換為[]。 如果您能夠控制以某種方式接收JSON的方式,那么我認為這可能是更好的解決方案,因為它與您請求的類型匹配,而無需對其進行任何進一步的操作。
Json.NET希望多維數組的格式類似於JSON文件中的3d鋸齒狀數組,但是您的格式像2d鋸齒狀數組的字典一樣。 您可以使用自定義JsonConverter
將這種格式的JSON轉換為3d數組,如下所示:
public class Array3DConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
if (!objectType.IsArray)
return false;
return objectType.GetArrayRank() == 3;
}
object ReadJsonGeneric<T>(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
if (reader.TokenType == JsonToken.StartArray)
{
// Handle case when it's actually a 3d array in the JSON.
var list = serializer.Deserialize<List<List<List<T>>>>(reader);
return list.Select((l, i) => new KeyValuePair<int, List<List<T>>>(i, l)).To3DArray();
}
else if (reader.TokenType == JsonToken.StartObject)
{
// Handle case when it's a dictionary of key/value pairs.
var dictionary = serializer.Deserialize<SortedDictionary<int, List<List<T>>>>(reader);
return dictionary.To3DArray();
}
else
{
throw new JsonSerializationException("Invalid reader.TokenType " + reader.TokenType);
}
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
try
{
var elementType = objectType.GetElementType();
var method = GetType().GetMethod("ReadJsonGeneric", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public);
return method.MakeGenericMethod(new[] { elementType }).Invoke(this, new object[] { reader, objectType, existingValue, serializer });
}
catch (TargetInvocationException ex)
{
// Wrap the TargetInvocationException in a JsonSerializerException
throw new JsonSerializationException("Failed to deserialize " + objectType, ex);
}
}
public override bool CanWrite { get { return false; } }
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
throw new NotImplementedException();
}
}
public static class EnumerableExtensions
{
public static T[,,] To3DArray<T>(this IEnumerable<KeyValuePair<int, List<List<T>>>> jaggedArray)
{
if (jaggedArray == null)
throw new ArgumentNullException("jaggedArray");
var counts = new int[3];
foreach (var pair in jaggedArray)
{
var i = pair.Key;
counts[0] = Math.Max(i + 1, counts[0]);
if (pair.Value == null)
continue;
var jCount = pair.Value.Count;
counts[1] = Math.Max(jCount, counts[1]);
for (int j = 0; j < jCount; j++)
{
if (pair.Value[j] == null)
continue;
var kCount = pair.Value[j].Count;
counts[2] = Math.Max(kCount, counts[2]);
}
}
var array = new T[counts[0], counts[1], counts[2]];
foreach (var pair in jaggedArray)
{
var i = pair.Key;
if (pair.Value == null)
continue;
var jCount = pair.Value.Count;
for (int j = 0; j < jCount; j++)
{
if (pair.Value[j] == null)
continue;
var kCount = pair.Value[j].Count;
for (int k = 0; k < kCount; k++)
array[i, j, k] = pair.Value[j][k];
}
}
return array;
}
}
然后像這樣使用它:
var array = JsonConvert.DeserializeObject<double[, ,]>(jsonString, new JsonSerializerSettings { Converters = new[] { new Array3DConverter() } });
或者,如果您已經將JSON字符串解析為JObject
,則可以使用JToken.ToObject<T>(JsonSerializer)
使用轉換器將其反序列化為所需的類型:
var array = jObj.ToObject<double[, ,]>(JsonSerializer.CreateDefault(new JsonSerializerSettings { Converters = new[] { new Array3DConverter() } }));
為了靈活使用,轉換器進行測試以查看傳入的JSON是否被格式化為對象或數組,並做出適當的響應。
注意-僅經過輕微測試。
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