如何重写JavaScriptSerializer.Deserialize<;T>;()
本文关键字:lt gt JavaScriptSerializer 何重写 重写 Deserialize | 更新日期: 2023-09-27 18:26:26
我得到一个json字符串,它几乎没有数据一致性问题。例如,json字符串中的一个字段返回字符串列表,而其他json字符串的同一字段返回字典(键、值对)。
我的类保存解析后的json值,该类的字段属性为List。由于这个数据一致性问题,json字符串无法正确解析。
以下是我解析json字符串的代码
JavaScriptSerializer serializer = new JavaScriptSerializer();
myClass mc = serializer.Deserialize<myClass>(jsonString);
有没有什么方法可以编写自定义代码来解析json字符串并将其映射到myClass?
您没有给出您试图实现的目标的具体示例,这意味着我们需要自己编一个示例。考虑以下类别:
public class myClass
{
public Dictionary<string, string> data { get; set; }
}
并考虑以下两个JSON字符串:
{"data": ["zero", 1, "two"]}
{"data": {"0": "zero", "1":1, "2":"two"}}
似乎您可能希望以相同的方式解析这些,将数组转换为键为数组索引的Dictionary<string, string>
。这可以通过以下JavaScriptConverter
:来实现
public class myClassConverter : JavaScriptConverter
{
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
var myClass = new myClass();
object data;
if (dictionary.TryGetValue("data", out data))
{
if (data.IsJsonArray())
{
myClass.data = data.AsJsonArray()
.Select((o, i) => new KeyValuePair<int, object>(i, o))
.ToDictionary(p => p.Key.ToString(NumberFormatInfo.InvariantInfo), p => serializer.ConvertToType<string>(p.Value));
}
else if (data.IsJsonObject())
{
myClass.data = data.AsJsonObject()
.ToDictionary(p => p.Key, p => serializer.ConvertToType<string>(p.Value));
}
}
return myClass;
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
throw new NotImplementedException();
}
public override IEnumerable<Type> SupportedTypes
{
get { return new [] { typeof(myClass) }; }
}
}
public static class JavaScriptSerializerObjectExtensions
{
public static bool IsJsonArray(this object obj)
{
if (obj is string || obj.IsJsonObject())
return false;
return obj is IEnumerable;
}
public static IEnumerable<object> AsJsonArray(this object obj)
{
return (obj as IEnumerable).Cast<object>();
}
public static bool IsJsonObject(this object obj)
{
return obj is IDictionary<string, object>;
}
public static IDictionary<string, object> AsJsonObject(this object obj)
{
return obj as IDictionary<string, object>;
}
}
传递给Deserialize()
的IDictionary<string, object>
对应于正在转换的JSON对象中的键/值对。对于一个特定的键(在这种情况下为"data"
),如果该值是JSON对象,则object
值将是IDictionary<string, object>
;如果该值为JSON数组,则为IEnumerable
(特别是ArrayList
)。通过根据适当的类型测试值,可以进行转换。
转换器只执行反序列化。像这样使用:
var jsonString1 = @"{""data"": [""zero"", 1, ""two""]}";
var jsonString2 = @"{""data"": {""0"": ""zero"", ""1"":1, ""2"":""two""}}";
var deserializer = new JavaScriptSerializer();
deserializer.RegisterConverters(new JavaScriptConverter[] { new myClassConverter() });
var newJson1 = new JavaScriptSerializer().Serialize(deserializer.Deserialize<myClass>(jsonString1));
var newJson2 = new JavaScriptSerializer().Serialize(deserializer.Deserialize<myClass>(jsonString2));
Console.WriteLine(newJson1); // Prints {"data":{"0":"zero","1":"1","2":"two"}}
Console.WriteLine(newJson2); // Prints {"data":{"0":"zero","1":"1","2":"two"}}
Debug.Assert(newJson1 == newJson2); // No assert