.net5 动态配置

通过自定义ConfigurationProvider可以实现从数据库获取参数，
同时读取配置仍然可以使用原本的IConfiguration

添加ConfigProvider 处理加载配置及定期刷新配置逻辑

 /// <summary>
 /// 配置提供者
 /// </summary>
 public class ConfigProvider : ConfigurationProvider, IDisposable
 {
     private bool isDisposed = false;
     public ConfigProvider()
     {
         //定时刷新配置
         ThreadPool.QueueUserWorkItem(obj =>
         {
             while (!isDisposed)
             {
                 Load();
                 Thread.Sleep(3 * 1000);
             }
         });
     }
     /// <summary>
     /// 读写锁
     /// </summary>
     private ReaderWriterLockSlim lockObj = new ReaderWriterLockSlim();
     public override IEnumerable<string> GetChildKeys(IEnumerable<string> earlierKeys, string parentPath)
     {
         lockObj.EnterReadLock();
         try
         {
             return base.GetChildKeys(earlierKeys, parentPath);
         }
         finally
         {
             lockObj.ExitReadLock();
         }
     }
     public override bool TryGet(string key, out string value)
     {
         lockObj.EnterReadLock();
         try
         {
             return base.TryGet(key, out value);
         }
         finally
         {
             lockObj.ExitReadLock();
         }
     }

     /// <summary>
     /// 更新数据
     /// </summary>
     public override void Load()
     {
         try
         {
             lockObj.EnterWriteLock();

             //加载配置，可以使用数据库
             var config = new
             {
                 AliOSSConfig = "127",
                 Port="1515"
             };


             Data["ReRoutesConfig"] = JsonConvert.SerializeObject(config);
         }
         finally
         {
             lockObj.ExitWriteLock();
         }
         OnReload();
     }


     public void Dispose()
     {
         isDisposed = true;
     }
 }

添加配置源继承IConfigurationSource，后续注入时需要使用此类型

/// <summary>
/// 配置源
/// </summary>
public class ConfigSource : IConfigurationSource
{
    public IConfigurationProvider Build(IConfigurationBuilder builder)
    {
        return new ConfigProvider();
    }
}

添加扩展方法

 public static class ConfigEx
 {
     /// <summary>
     /// 自定义扩展，增加配置 
     /// </summary>
     public static IConfigurationBuilder AddCustomConfig(this IConfigurationBuilder builder, IConfiguration configuration = null)
     {
         if (builder == null)
         {
             throw new ArgumentNullException(nameof(builder));
         }

         return builder.Add(new ConfigSource());
     }
 }

startup中加载动态配置

 Host.CreateDefaultBuilder(args)
     .ConfigureAppConfiguration(conf =>
     {
         conf.AddCustomConfig();
     })

测试使用

//configuration通过依赖注入获取   IConfiguration configuration;
var Endpoint = configuration.GetValue<string>("ReRoutesConfig");