C# 如何删除json字符串中的空值

How to remove null value in json string

提问by user2199888

Hi I'm using the below class

嗨，我正在使用以下课程

Public List<string> name;
Public List<string> midname;

Once I serialize it I'm getting the following output like

一旦我序列化它，我就会得到以下输出

 {"name":[hari],"midname":null}

But I want my answer to be like this

但我希望我的答案是这样的

{"name":[hari]}

It shouldn't display the class attribute that has null value and I'm using c# .net framework.

它不应该显示具有空值的类属性，我使用的是 c# .net 框架。

回答by p.s.w.g

The full answer depends on how you're serializing your class.

完整的答案取决于您如何序列化您的课程。

If you're using data contracts to serialize your classes, set EmitDefaultValue = false

如果您使用数据协定来序列化您的类，请设置 EmitDefaultValue = false

[DataContract]
class MyClass
{
    [DataMember(EmitDefaultValue = false)]
    public List<string> name;

    [DataMember(EmitDefaultValue = false)]
    public List<string> midname { get; set; }
}

If you're using Json.Net, try this instead

如果你使用的是Json.Net，试试这个

class MyClass
{
    [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
    public List<string> name;

    [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
    public List<string> midname { get; set; }
}

Or set it globally with JsonSerializerSettings.NullValueHandling = NullValueHandling.Ignore

或者全局设置 JsonSerializerSettings.NullValueHandling = NullValueHandling.Ignore

回答by Sachin

If you are using Json.Netthen You can try this by Decorating your property like this

如果您正在使用，Json.Net那么您可以通过像这样装饰您的财产来尝试这个

[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
public List<string> name { get; set; }

回答by tam tam

private class NullPropertiesConverter : JavaScriptConverter
{
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        var jsonExample = new Dictionary<string, object>();
        foreach (var prop in obj.GetType().GetProperties())
        {
            //check if decorated with ScriptIgnore attribute
            bool ignoreProp = prop.IsDefined(typeof(ScriptIgnoreAttribute), true);

            var value = prop.GetValue(obj, BindingFlags.Public, null, null, null);
            if (value != null && !ignoreProp)
                jsonExample.Add(prop.Name, value);
        }

        return jsonExample;
    }

    public override IEnumerable<Type> SupportedTypes
    {
        get { return GetType().Assembly.GetTypes(); }
    }
}

The following is how you will utilize the above and it will ignore null values.

以下是您将如何利用上述内容，它将忽略空值。

var serializer = new JavaScriptSerializer();
    serializer.RegisterConverters(new JavaScriptConverter[] { new NullPropertiesConverter() });
    return serializer.Serialize(someObjectToSerialize);

Source

来源

回答by mehman abasov

string signatureJson = JsonConvert.SerializeObject(signature, Newtonsoft.Json.Formatting.Indented, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });

string signatureJson = JsonConvert.SerializeObject(signature, Newtonsoft.Json.Formatting.Indented, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });

回答by Daniel Mohr

Like p.s.w.g said, best to serialize properly in the first place. An example of serializing without nulls can be seen here

就像pswg所说的那样，最好首先正确序列化。可以在此处看到没有空值的序列化示例

e.g.

例如

var json = JsonConvert.SerializeObject(
        objectToSerialize,
        new JsonSerializerSettings {NullValueHandling = NullValueHandling.Ignore});