C# 将 Json 字符串转换为 Object

Question

我已经尝试让它工作 4 天了，但我似乎无法弄清楚。我通过 api 接收 json 字符串，并希望将数据解析为不同的字符串和整数：

Json 字符串示例：

"[{\"Entry_number\":\"4\",\"Entry_date\":\"2019-01-10 18:22:55\",\"Customer_number\":\"16\",\"Entry_value\":\"13\",\"Comment\":\"Nu gaat ie t GVD doen\"},
    {\"Entry_number\":\"5\",\"Entry_date\":\"2019-01-12 14:34:23\",\"Customer_number\":\"16\",\"Entry_value\":\"10\",\"Comment\":\"TextBox\"},
    {\"Entry_number\":\"6\",\"Entry_date\":\"2019-01-12 14:34:31\",\"Customer_number\":\"16\",\"Entry_value\":\"10\",\"Comment\":\"Onrustig\"},
    {\"Entry_number\":\"7\",\"Entry_date\":\"2019-01-12 14:34:37\",\"Customer_number\":\"16\",\"Entry_value\":\"10\",\"Comment\":\"Ziek\"}]"

我想转换成什么：

public class SleepEntry
{
    string Entry_number;
    string Entry_date;
    string Customer_number;
    string Entry_value;
    string Comment;

    public string Entry_number1 { get => Entry_number; set => Entry_number = value; }

    public string Entry_date1 { get => Entry_date; set => Entry_date = value; }

    public string Customer_number1 { get => Customer_number; set => Customer_number = value; }

    public string Entry_value1 { get => Entry_value; set => Entry_value = value; }

    public string Comment1 { get => Comment; set => Comment = value; }
}

public class SleepData
{
    private List<SleepEntry> plants; 

    public List<SleepEntry> Plants { get => plants; set => plants = value; }
}

读取json的代码：

    public void Get_Monthly_Data()
    {


        StreamReader reader = new StreamReader(@"C:\Users\Ruben\source\repos\Health App Goede\Health App Goede\Resources\Cutstomer_ID.txt");
        Customernumber = reader.ReadLine();
        reader.Close();
        //string json = entrys();

        //convert json to series objects
        SleepData sleepdata = JsonConvert.DeserializeObject<SleepData>(entrys());

    }

    public string entrys()
    {
        string json = get.get_customer_monitoring_entry("sleep", Customernumber);

        return json;
    }

现在我想尝试检查每个条目是否是本周的数据。然后只需获取本周每个条目的 Entry_value 并暂时将其显示在文本框中。任何帮助或提示将非常感激。

Answer 1

您实际上并不需要这些支持字段。您可以将它们编写为自动属性{ get; set; }。

JSON 中有一些非常烦人的东西，即日期和数字作为字符串。因此，我建议您使用QuickType之类的工具来为您生成 C# 模型类。

结果如下：

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

public partial class SleepEntry
{
    [JsonProperty("Entry_number")]
    [JsonConverter(typeof(ParseStringConverter))]
    public long EntryNumber { get; set; }

    [JsonProperty("Entry_date")]
    public DateTimeOffset EntryDate { get; set; }

    [JsonProperty("Customer_number")]
    [JsonConverter(typeof(ParseStringConverter))]
    public long CustomerNumber { get; set; }

    [JsonProperty("Entry_value")]
    [JsonConverter(typeof(ParseStringConverter))]
    public long EntryValue { get; set; }

    [JsonProperty("Comment")]
    public string Comment { get; set; }
}

public partial class SleepEntry
{
    public static SleepEntry[] FromJson(string json) => JsonConvert.DeserializeObject<SleepEntry[]>(json, QuickType.Converter.Settings);
}

public static class Serialize
{
    public static string ToJson(this SleepEntry[] self) => JsonConvert.SerializeObject(self, QuickType.Converter.Settings);
}

internal static class Converter
{
    public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
    {
        MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
        DateParseHandling = DateParseHandling.None,
        Converters =
        {
            new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
        },
    };
}

internal class ParseStringConverter : JsonConverter
{
    public override bool CanConvert(Type t) => t == typeof(long) || t == typeof(long?);

    public override object ReadJson(JsonReader reader, Type t, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null) return null;
        var value = serializer.Deserialize<string>(reader);
        long l;
        if (Int64.TryParse(value, out l))
        {
            return l;
        }
        throw new Exception("Cannot unmarshal type long");
    }

    public override void WriteJson(JsonWriter writer, object untypedValue, JsonSerializer serializer)
    {
        if (untypedValue == null)
        {
            serializer.Serialize(writer, null);
            return;
        }
        var value = (long)untypedValue;
        serializer.Serialize(writer, value.ToString());
        return;
    }

    public static readonly ParseStringConverter Singleton = new ParseStringConverter();
}

用法：

// sleepEntries is a SleepEntry[]
var sleepEntries = SleepEntry.FromJson(jsonString);

现在我想尝试检查每个条目是否是本周的数据。然后只需获取本周每个条目的 Entry_value 并暂时将其显示在文本框中。

要确定两个日期时间是否在同一周，我们可以使用以下方法：

private bool DatesAreInTheSameWeek(DateTime date1, DateTime date2)
{
    var cal = System.Globalization.DateTimeFormatInfo.CurrentInfo.Calendar;
    var d1 = date1.Date.AddDays(-1 * (int)cal.GetDayOfWeek(date1));
    var d2 = date2.Date.AddDays(-1 * (int)cal.GetDayOfWeek(date2));

    return d1 == d2;
}

复制自这个问题。

然后这可以通过一点 LINQ 来完成：

List<long> list = sleepEntries.Where(x => DatesAreInTheSameWeek(x.EntryDate.DateTime, DateTime.Now)).Select(x => x.EntryValue).ToList();