C# Json序列化的格式化问题

问题来源:  客户要求传送给他的JSON文件的float型格式化为2位小数,数值型有30-40个栏位,一个一个修改也不是很好.

bing和百度找到的方式都是自己定义一个JsonConverter,进行格式化.

找到的都是在字符串两边加++的例子,核心转化的代码如下:

class StringFormatConverter : JsonConverter
{
    public string Format { get; set; }

    public override void WriteJson (JsonWriter writer, object value, JsonSerializer serializer)
    {
        writer.WriteValue(string.Format(Format, value));
    }

    public override object ReadJson (JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotSupportedException();
    }

    public override bool CanConvert (Type objectType)
    {
        return objectType == typeof(string);
    }
}

Console.WriteLine(JsonConvert.SerializeObject(new List<Foo> {
    new Foo { FooId = 1, Name = "FooName", Description = "Bla bla bla" }
}, new JsonSerializerSettings {
    Converters = { new StringFormatConverter { Format = "++{0}++" } }
}));

按照它的思路进行修改一版(此时的格式化格式写死的,准备搞定之后再修改):

class FloatFormatConverter : JsonConverter
{
    public string Format { get; set; }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
          writer.WriteValue(string.Format("{0:f2}", value));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotSupportedException();
    }

    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(float) || objectType == typeof(double);
    }
}

发现问题: 1)数字变成了字符  (比如: "Height": "28.2")     2)Json的整体的换行格式化(Formatting.Indented)  需要加进去

多次尝试之后的最终版本,达到了最后的要求

 context.Response.Write(JsonConvert.SerializeObject(new { errcode = 1000, errmsg = edi },
            Formatting.Indented,
            new FloatFormatConverter { Format = "0.##" }));



class FloatFormatConverter : JsonConverter
{
    public string Format { get; set; }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
       
        writer.WriteValue(Convert.ToDouble(((float)value).ToString(Format)));
    }

终于搞定了.

 

 

 

参考网站

https://stackoverflow.com/questions/15810087/how-to-format-properties-that-are-only-string-in-an-object-while-converting-to-j