如何遍历从appSettings.json配置的Devices类属性

我有一个appSettings.json文件，其中包含如下Devices配置组：

"Devices": {
  "_850347_74Crompton1": "3605",
  "_850532_41Crompton2": "813",
  "_850722_18IMEElectricity": "707",
  "_850766_85DustNoise1": "306",
  "_850772_63Dustnoise2": "2866",
  "_850774_29DustNoise3": "3104",
  "_863859_63Level": "22601",
  "_864233_30": "713",
  "_864319_07noise": "606"
}

对应的Devices类定义如下：

public class Devices
{
    public string _850347_74Crompton1 { get; set; }
    public string _850532_41Crompton2 { get; set; }
    public string _850722_18IMEElectricity { get; set; }
    public string _850766_85DustNoise1 { get; set; }
    public string _850772_63Dustnoise2 { get; set; }
    public string _850774_29DustNoise3 { get; set; }
    public string _863859_63Level { get; set; }
    public string _864233_30 { get; set; }
    public string _864319_07noise { get; set; }
}

我可以通过以下方式获取该对象的值：

var myDevice = config.GetRequiredSection("Devices").Get<Devices>();

也能直接访问指定属性值，例如：

var myValue = myDevice._850347_74Crompton1;
var anotherValue = myDevice._864233_30;

但我不想硬编码属性名，希望遍历所有属性，尝试的代码无法正常工作，要么返回null要么类型不正确。更新后尝试如下代码出现错误：

Devices iot = config.GetRequiredSection("Devices").Get<Devices>();

foreach (Devices device in iot)
{
   ...
}

错误信息：

Severity Code Description Project File Line Suppression State
Error CS1579 foreach statement cannot operate on variables of type
'appSettings.Devices' because 'appSettings.Devices' does not contain a
public instance or extension definition for
'GetEnumerator' IoT_CaptisDataCapture .....\Program.cs 60 Active

请问如何实现遍历Devices类的属性？

方法1：使用反射遍历类的属性 #

通过反射获取Devices对象的所有公共属性，遍历读取属性名和值：

Devices iot = config.GetRequiredSection("Devices").Get<Devices>();

// 获取所有公共实例属性
var properties = typeof(Devices).GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);

foreach (var prop in properties)
{
    string propName = prop.Name;
    string propValue = prop.GetValue(iot) as string;
    // 按需处理属性名和值，例如打印
    Console.WriteLine($"{propName}: {propValue}");
}

方法2：直接从配置节获取键值对 #

无需反序列化为Devices对象，直接读取配置节的子项：

var devicesSection = config.GetRequiredSection("Devices");

foreach (var child in devicesSection.GetChildren())
{
    string deviceKey = child.Key;
    string deviceValue = child.Value;
    Console.WriteLine($"{deviceKey}: {deviceValue}");
}

方法3：修改Devices类实现可枚举接口 #

如果希望直接用foreach遍历Devices对象，让类实现IEnumerable<KeyValuePair<string, string>>，手动返回属性的键值对：

public class Devices : IEnumerable<KeyValuePair<string, string>>
{
    public string _850347_74Crompton1 { get; set; }
    public string _850532_41Crompton2 { get; set; }
    public string _850722_18IMEElectricity { get; set; }
    public string _850766_85DustNoise1 { get; set; }
    public string _850772_63Dustnoise2 { get; set; }
    public string _850774_29DustNoise3 { get; set; }
    public string _863859_63Level { get; set; }
    public string _864233_30 { get; set; }
    public string _864319_07noise { get; set; }

    public IEnumerator<KeyValuePair<string, string>> GetEnumerator()
    {
        yield return new KeyValuePair<string, string>(nameof(_850347_74Crompton1), _850347_74Crompton1);
        yield return new KeyValuePair<string, string>(nameof(_850532_41Crompton2), _850532_41Crompton2);
        yield return new KeyValuePair<string, string>(nameof(_850722_18IMEElectricity), _850722_18IMEElectricity);
        yield return new KeyValuePair<string, string>(nameof(_850766_85DustNoise1), _850766_85DustNoise1);
        yield return new KeyValuePair<string, string>(nameof(_850772_63Dustnoise2), _850772_63Dustnoise2);
        yield return new KeyValuePair<string, string>(nameof(_850774_29DustNoise3), _850774_29DustNoise3);
        yield return new KeyValuePair<string, string>(nameof(_863859_63Level), _863859_63Level);
        yield return new KeyValuePair<string, string>(nameof(_864233_30), _864233_30);
        yield return new KeyValuePair<string, string>(nameof(_864319_07noise), _864319_07noise);
    }

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

之后即可直接用foreach遍历：

Devices iot = config.GetRequiredSection("Devices").Get<Devices>();

foreach (var kvp in iot)
{
    Console.WriteLine($"{kvp.Key}: {kvp.Value}");
}

内容的提问来源于stack exchange，提问作者Fandango68