如何实现支持多Exchange节点的App.Config自定义嵌套配置节

第一步：修复ExchangeFeatures类的属性赋值错误 #

原代码中属性的set方法逻辑错误，需修正为正确的赋值方式：

namespace AppWithConfigs
{
    public class ExchangeFeatures : ConfigurationElement
    {
        [ConfigurationProperty("Name", IsRequired = true)]
        public string Name
        {
            get { return (string)this["Name"]; }
            set { this["Name"] = value; }
        }

        [ConfigurationProperty("ApiKey", IsRequired = true)]
        public string ApiKey
        {
            get { return (string)this["ApiKey"]; }
            set { this["ApiKey"] = value; }
        }

        [ConfigurationProperty("ApiSecret", IsRequired = true)]
        public string ApiSecret
        {
            get { return (string)this["ApiSecret"]; }
            set { this["ApiSecret"] = value; }
        }

        [ConfigurationProperty("ApiPassPhrase", IsRequired = false)]
        public string ApiPassPhrase
        {
            get { return (string)this["ApiPassPhrase"]; }
            set { this["ApiPassPhrase"] = value; }
        }
    }
}

第二步：创建配置元素集合类 #

新增继承自ConfigurationElementCollection的类，用于管理多个ExchangeFeatures节点：

public class ExchangeElementCollection : ConfigurationElementCollection
{
    protected override ConfigurationElement CreateNewElement()
    {
        return new ExchangeFeatures();
    }

    protected override object GetElementKey(ConfigurationElement element)
    {
        return ((ExchangeFeatures)element).Name;
    }

    public override ConfigurationElementCollectionType CollectionType => ConfigurationElementCollectionType.BasicMap;

    protected override string ElementName => "Exchange";

    public ExchangeFeatures this[int index]
    {
        get { return (ExchangeFeatures)BaseGet(index); }
        set
        {
            if (BaseGet(index) != null)
                BaseRemoveAt(index);
            BaseAdd(index, value);
        }
    }

    public new ExchangeFeatures this[string name]
    {
        get { return (ExchangeFeatures)BaseGet(name); }
    }
}

第三步：修改ExchangeSetting配置节类 #

将原来单个ExchangeFeatures属性替换为集合属性：

public class ExchangeSetting : ConfigurationSection
{
    [ConfigurationProperty("", IsDefaultCollection = true)]
    public ExchangeElementCollection Exchanges
    {
        get { return (ExchangeElementCollection)this[""]; }
    }
}

第四步：更新App.config配置文件 #

现在可以直接添加多个Exchange节点：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="ExchangeSetting" type="AppWithConfigs.ExchangeSetting, AppWithConfigs"/>
    </configSections>

    <ExchangeSetting>
        <Exchange Name="Binance" ApiKey="B-Key" ApiSecret="B-Secret" ApiPassPhrase="B-Phrase" />
        <Exchange Name="Coinbase" ApiKey="C-Key" ApiSecret="C-Secret" ApiPassPhrase="C-Phrase" />
        <!-- 可继续添加更多Exchange节点 -->
    </ExchangeSetting>
        
</configuration>

第五步：修改Program类遍历所有配置 #

更新Main方法，遍历输出所有交易所配置：

public class Program
{
    static void Main(string[] args)
    {
        var exchangeSetting = ConfigurationManager.GetSection("ExchangeSetting") as ExchangeSetting;

        if (exchangeSetting != null && exchangeSetting.Exchanges.Count > 0)
        {
            foreach (ExchangeFeatures exchange in exchangeSetting.Exchanges)
            {
                Console.WriteLine($"===== 交易所：{exchange.Name} =====");
                Console.WriteLine($"ApiKey = {exchange.ApiKey}");
                Console.WriteLine($"ApiSecret = {exchange.ApiSecret}");
                Console.WriteLine($"ApiPassPhrase = {exchange.ApiPassPhrase ?? "未设置"}");
                Console.WriteLine();
            }
        }
        else
        {
            Console.WriteLine("未找到任何交易所配置");
        }

        Console.ReadKey();
    }
}

修改完成后，程序即可支持多个Exchange节点，正常遍历获取所有配置信息。

内容的提问来源于stack exchange，提问作者Zaken