ASP.NET - JSON 相關筆記

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C# 與 Json 相關的筆記

基本的序列化跟反序列化

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using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

//建立類別
public class Person 
{
    public string Name { get; set; }
    public int Age { get; set; }
}

//基本的 序列化輸出模樣 + 反序列化
protected void Page_Load(object sender, EventArgs e)
{
    //給值
    Person myPerson = new Person();
    myPerson.Name = "Stoenr";
    myPerson.Age = 18;

    //序列化
    // Formatting.Indented 會生成良好的顯示格式
    // Formatting.None會跳過不必要的空格和換行符號，讓Json的結果更小。生成的顯示格式更加緊湊，也許效率更高。
    string output = JsonConvert.SerializeObject(myPerson, Formatting.Indented);
    Response.Write(output);

    //反序列化
    Person book2 = JsonConvert.DeserializeObject<Person>(output);
    string output2 = string.Format("<br/>Name：{0}，Age：{1}", book2.Name, book2.Age);
    Response.Write(output2);

    //Json 查詢
    JObject myQuery = JsonConvert.DeserializeObject<JObject>(output);
    string output3 = string.Format("<br/>Query：{0}", myQuery.GetValue("Name")); //myQuery["Name"]
    Response.Write(output3);
}

//Response output：
//{"Name":"Stoenr","Age":18}

//Response output2：
//Name：Stoenr，Age：18

如果在類別中有某些屬性,要在序列化時跳過的話

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using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Converters;

public enum Options
{
    Option1, Option2
}

public class Entity
{
    public Options A1 { get; set; }
    public Options A2 { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Options B1 { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Options B2 { get; set; }
    public string P1 { get; set; }
    [JsonIgnore]
    public string P2 { get; set; }
}

protected void Page_Load(object sender, EventArgs e)
{
    Entity myEntity = new Entity()
    {
        A1 = Options.Option1,
        A2 = Options.Option2,
        B1 = Options.Option1,
        B2 = Options.Option2,
        P1 = "P1",
        P2 = "P2"
    };
    string output4 = JsonConvert.SerializeObject(myEntity, Formatting.Indented);
    Response.Write("<br/>" + output4);
}

//Response output4
//{ "A1": 0, "A2": 1, "B1": "Option1", "B2": "Option2", "P1": "P1" }

但如果是類別中只需要少部分指定的屬性要被序列化，也可以這樣子設定

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using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Runtime.Serialization;

[DataContract]
public class Computer
{
    //序列化
    [DataMember]
    public string Name { get; set; }
    [DataMember]
    public decimal SalePrice { get; set; }

    //忽略
    public string Manufacture { get; set; }
    public int StockCount { get; set; }
    public decimal WholeSalePrice { get; set; }
    public DateTime NextShipmentDate { get; set; }
}

跳過為null值

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public class Movie
{
    public string Name { get; set; }
    public string Description { get; set; }
    public string Classification { get; set; }
    public string Studio { get; set; }
    public DateTime? ReleaseDate { get; set; }
    public List<string> ReleaseCountries { get; set; }
}

protected void Page_Load(object sender, EventArgs e)
{
    Movie movie = new Movie();
    movie.Name = "The Best Offer";
    movie.Description = "Good Movie";

    string ignored = JsonConvert.SerializeObject(movie,
        Formatting.Indented,
        new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
}

//Response 
//{ Name": "The Best Offer","Description": "Good Movie" }

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