C#: JSON والتسلسل

{
  "name": "Zhang San",
  "age": 28,
  "isStudent": false,
  "hobbies": ["programming", "reading"],
  "address": {
    "city": "Beijing",
    "zip": "100000"
  }
}

using System.Text.Json;

using System;
using System.Text.Json;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public bool IsStudent { get; set; }
}

class Program
{
    static void Main()
    {
        var person = new Person
        {
            Name = "Zhang San",
            Age = 28,
            IsStudent = false
        };
        string json = JsonSerializer.Serialize(person);
        Console.WriteLine(json);
    }
}

{"Name":"Zhang San","Age":28,"IsStudent":false}

using System;
using System.Text.Json;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public bool IsStudent { get; set; }
}

class Program
{
    static void Main()
    {
        string json = @"{""Name"":""Zhang San"",""Age"":28,""IsStudent"":false}";
        Person person = JsonSerializer.Deserialize<Person>(json);
        Console.WriteLine($"Name: {person.Name}, Age: {person.Age}");
    }
}

Name: Zhang San, Age: 28

using System;
using System.Text.Json;

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
}

class Program
{
    static void Main()
    {
        var person = new Person
        {
            Name = "Zhang San",
            Age = 28,
            Email = null
        };

        var options = new JsonSerializerOptions
        {
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
            WriteIndented = true,
            IgnoreNullValues = true
        };

        string json = JsonSerializer.Serialize(person, options);
        Console.WriteLine(json);
    }
}

{
  "name": "Zhang San",
  "age": 28
}

using System;
using System.Collections.Generic;
using System.Text.Json;

public class Student
{
    public string Name { get; set; }
    public int Score { get; set; }
}

class Program
{
    static void Main()
    {
        var students = new List<Student>
        {
            new Student { Name = "Zhang San", Score = 90 },
            new Student { Name = "Li Si", Score = 85 },
            new Student { Name = "Wang Wu", Score = 92 }
        };

        var options = new JsonSerializerOptions { WriteIndented = true };
        string json = JsonSerializer.Serialize(students, options);
        Console.WriteLine(json);

        var scores = new Dictionary`<string, int>`
        {
            ["Chinese"] = 90,
            ["Math"] = 95,
            ["English"] = 88
        };
        string dictJson = JsonSerializer.Serialize(scores, options);
        Console.WriteLine(dictJson);
    }
}

[
  {
    "Name": "Zhang San",
    "Score": 90
  },
  {
    "Name": "Li Si",
    "Score": 85
  },
  {
    "Name": "Wang Wu",
    "Score": 92
  }
]
{
  "Chinese": 90,
  "Math": 95,
  "English": 88
}

using System;
using System.Text.Json;

class Program
{
    static void Main()
    {
        string json = @"{""name"":""Zhang San"",""age"":28,""hobbies"":[""programming"",""reading""]}";

        using JsonDocument doc = JsonDocument.Parse(json);
        JsonElement root = doc.RootElement;

        string name = root.GetProperty("name").GetString();
        int age = root.GetProperty("age").GetInt32();
        JsonElement hobbies = root.GetProperty("hobbies");

        Console.WriteLine($"Name: {name}, Age: {age}");
        foreach (JsonElement hobby in hobbies.EnumerateArray())
        {
            Console.WriteLine($"Hobby: {hobby.GetString()}");
        }
    }
}

Name: Zhang San, Age: 28
Hobby: programming
Hobby: reading

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

public class DateOnlyConverter : JsonConverter`<DateTime>`
{
    public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
        return DateTime.ParseExact(reader.GetString(), "yyyy-MM-dd", null);
    }

    public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
    {
        writer.WriteStringValue(value.ToString("yyyy-MM-dd"));
    }
}

public class Event
{
    public string Title { get; set; }

    [JsonConverter(typeof(DateOnlyConverter))]
    public DateTime Date { get; set; }
}

class Program
{
    static void Main()
    {
        var evt = new Event
        {
            Title = "Product Launch",
            Date = new DateTime(2025, 6, 15)
        };

        string json = JsonSerializer.Serialize(evt);
        Console.WriteLine(json);

        Event deserialized = JsonSerializer.Deserialize<Event>(json);
        Console.WriteLine($"Title: {deserialized.Title}, Date: {deserialized.Date:yyyy-MM-dd}");
    }
}

{"Title":"Product Launch","Date":"2025-06-15"}
Title: Product Launch, Date: 2025-06-15

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json;

public class Student
{
    public string Name { get; set; }
    public int Score { get; set; }
    public string City { get; set; }
}

class Program
{
    static void Main()
    {
        string json = @"[
            {""Name"":""Zhang San"",""Score"":90,""City"":""Beijing""},
            {""Name"":""Li Si"",""Score"":85,""City"":""Shanghai""},
            {""Name"":""Wang Wu"",""Score"":92,""City"":""Beijing""},
            {""Name"":""Zhao Liu"",""Score"":78,""City"":""Shanghai""},
            {""Name"":""Qian Qi"",""Score"":95,""City"":""Beijing""}
        ]";

        List<Student> students = JsonSerializer.Deserialize<List<Student>>(json);

        var beijingTop = students
            .Where(s => s.City == "Beijing")
            .OrderByDescending(s => s.Score)
            .ToList();

        Console.WriteLine("Beijing students (sorted by score, descending):");
        foreach (var s in beijingTop)
        {
            Console.WriteLine($"  {s.Name}: {s.Score}");
        }

        var cityAvg = students
            .GroupBy(s => s.City)
            .Select(g => new { City = g.Key, Avg = g.Average(s => s.Score) });

        Console.WriteLine("\nAverage score by city:");
        foreach (var item in cityAvg)
        {
            Console.WriteLine($"  {item.City}: {item.Avg:F1}");
        }
    }
}

Beijing students (sorted by score, descending):
  Qian Qi: 95
  Wang Wu: 92
  Zhang San: 90

Average score by city:
  Beijing: 92.3
  Shanghai: 81.5

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Program
{
    static void Main()
    {
        var records = new List<string[]>
        {
            new[] { "Name", "Age", "City" },
            new[] { "Zhang San", "28", "Beijing" },
            new[] { "Li Si", "25", "Shanghai" }
        };

        string csvPath = "data.csv";
        File.WriteAllLines(csvPath, records.Select(r => string.Join(",", r)));

        string[] lines = File.ReadAllLines(csvPath);
        foreach (string line in lines)
        {
            string[] fields = line.Split(',');
            Console.WriteLine($"{fields[0],-10} {fields[1],-4} {fields[2]}");
        }
    }
}

Name       Age   City
Zhang San  28    Beijing
Li Si      25    Shanghai