dotnetcore配置框架简介
- 2020 年 5 月 2 日
- 筆記
一、前言
配置的本质就是字符串的键值对,微软的一系列接口其实就是对这些键值对字符串的抽象。
二、基本类型
2.1、Nuget包
- Microsoft.Extensions.Configuration.Abstractions
- Microsoft.Extensions.Configuration
2.2、抽象接口
- IConfiguration
- 提供了查询、设置配置项、监控变化等方法
- IConfigurationRoot
- 在IConfiguration接口基础上,增加了 Reload 方法强制从provider中重新加载配置值
- IConfigurationSection
- 对配置节点的抽象
- IConfigurationBuilder
- 根据提供的数据源注册并构建IConfiguration
- IConfigurationSource
- 对数据源的抽象,例如Json、xml、环境变量、内存变量等
- IConfigurationProvider
- 规定了配置项的获取、设置、重载等统一的行为
三、基本配置
注:各种配置方式的目的是在控制台中输出以下内容,如下图:
3.1、加载内存中的配置
- 需要引入包:Microsoft.Extensions.Configuration
- 主要方法:builder.AddInMemoryCollection()
static void Main(string[] args) { IConfigurationBuilder builder = new ConfigurationBuilder(); var memoryData = new Dictionary<string, string>(); memoryData.Add("Student:Code", "10002385"); memoryData.Add("Student:Name", "LiuSan"); builder.AddInMemoryCollection(memoryData); IConfigurationRoot configurationRoot = builder.Build(); IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); Console.WriteLine($"Code:{configurationSection["Code"]}"); Console.WriteLine($"Name:{configurationSection["Name"]}"); Console.Read(); }
3.2、加载环境变量中的配置
- 需要引入包:Microsoft.Extensions.Configuration.EnvironmentVariables
- 主要方法:builder.AddEnvironmentVariables()
- 环境变量中层级关系使用 __ 代替 :
1 static void Main(string[] args) 2 { 3 IConfigurationBuilder builder = new ConfigurationBuilder(); 4 builder.AddEnvironmentVariables(); 5 IConfigurationRoot configurationRoot = builder.Build(); 6 IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); 7 8 Console.WriteLine($"Code:{configurationSection["Code"]}"); 9 Console.WriteLine($"Name:{configurationSection["Name"]}"); 10 11 Console.Read(); 12 }
3.3、加载命令行中的配置
- 需要引入包:Microsoft.Extensions.Configuration.CommandLine
- 主要方法:builder.AddCommandLine(args)
- 命令行中使用–表示配置项,层级关系使用:
1 static void Main(string[] args) 2 { 3 IConfigurationBuilder builder = new ConfigurationBuilder(); 4 builder.AddCommandLine(args); 5 IConfigurationRoot configurationRoot = builder.Build(); 6 IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); 7 8 Console.WriteLine($"Code:{configurationSection["Code"]}"); 9 Console.WriteLine($"Name:{configurationSection["Name"]}"); 10 11 Console.Read(); 12 }
3.4、加载Json中的配置
- 需要引入包:Microsoft.Extensions.Configuration.Json
- 主要方法:builder.AddJsonFile(“appsettings.json”)
1 static void Main(string[] args) 2 { 3 IConfigurationBuilder builder = new ConfigurationBuilder(); 4 builder.AddJsonFile("appsettings.json"); 5 IConfigurationRoot configurationRoot = builder.Build(); 6 IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); 7 8 Console.WriteLine($"Code:{configurationSection["Code"]}"); 9 Console.WriteLine($"Name:{configurationSection["Name"]}"); 10 11 Console.Read(); 12 }
3.5、加载xml中的配置
- 需要引入包:Microsoft.Extensions.Configuration.Xml
- 主要方法:builder.AddXmlFile(“appsettings.xml”)
- xml中不会读取最外层,所以Section必需从第二层开始
1 static void Main(string[] args) 2 { 3 IConfigurationBuilder builder = new ConfigurationBuilder(); 4 builder.AddXmlFile("appsettings.xml"); 5 IConfigurationRoot configurationRoot = builder.Build(); 6 IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); 7 8 Console.WriteLine($"Code:{configurationSection["Code"]}"); 9 Console.WriteLine($"Name:{configurationSection["Name"]}"); 10 11 Console.Read(); 12 }
四、高级配置
4.1、将配置绑定至强对象
- 需要引入包:Microsoft.Extensions.Configuration.Binder
- 主要方法:configurationRoot.GetSection(“Student”).Bind(student)
1 class Program 2 { 3 static void Main(string[] args) 4 { 5 IConfigurationBuilder builder = new ConfigurationBuilder(); 6 builder.AddJsonFile("appsettings.json"); 7 IConfigurationRoot configurationRoot = builder.Build(); 8 9 var student = new Student(); 10 configurationRoot.GetSection("Student").Bind(student); 11 12 Console.WriteLine($"Code:{student.Code}"); 13 Console.WriteLine($"Name:{student.Name}"); 14 15 Console.Read(); 16 } 17 } 18 19 class Student 20 { 21 public string Code { get; set; } 22 23 public string Name { get; set; } 24 }
4.2、IOptions
- 需要引入包:Microsoft.Extensins.Options
- 需要引入包:Microsoft.Extensions.Options.ConfigurationExtensions
- 本质其实就是将一个Section配置节点映射到一个实体对象
1 class Program 2 { 3 static void Main(string[] args) 4 { 5 IConfigurationBuilder builder = new ConfigurationBuilder(); 6 builder.AddJsonFile("appsettings.json"); 7 IConfigurationRoot configurationRoot = builder.Build(); 8 9 IServiceCollection services = new ServiceCollection(); 10 services.Configure<WeixinOptions>(configurationRoot.GetSection("WeixinSetting")); 11 services.AddScoped<IWeixinService, WeixinService>(); 12 13 var provider = services.BuildServiceProvider(); 14 var weixinService = provider.GetService<IWeixinService>(); 15 string appId = weixinService.AppId; 16 string token = weixinService.Token; 17 18 Console.Read(); 19 } 20 } 21 22 interface IWeixinService 23 { 24 string AppId { get; } 25 string Token { get; } 26 } 27 28 class WeixinService: IWeixinService 29 { 30 IOptions<WeixinOptions> _options; 31 public WeixinService(IOptions<WeixinOptions> options) 32 { 33 _options = options; 34 } 35 36 public string AppId { get => _options.Value.AppId; } 37 public string Token { get => _options.Value.Token;} 38 } 39 40 class WeixinOptions 41 { 42 public string AppId { get; set; } 43 44 public string Token { get; set; } 45 }
4.3、热更新
- IConfigurationBuilder添加数据源时设置reloadOnChange=true
- 监听的核心方法:var token = configurationRoot.GetReloadToken()
1 static void Main(string[] args) 2 { 3 IConfigurationBuilder builder = new ConfigurationBuilder(); 4 builder.AddJsonFile("appsettings.json", optional:false, reloadOnChange:true); 5 IConfigurationRoot configurationRoot = builder.Build(); 6 IConfigurationSection configurationSection = configurationRoot.GetSection("Student"); 7 8 var token = configurationRoot.GetReloadToken(); 9 ChangeToken.OnChange(() => configurationRoot.GetReloadToken(), () => 10 { 11 Console.WriteLine("配置发生改变了..."); 12 Console.WriteLine($"Code:{configurationSection["Code"]}"); 13 Console.WriteLine($"Name:{configurationSection["Name"]}"); 14 }); 15 16 Console.Read(); 17 }
五、总结
- 配置就是key-value键值对字符串
- IConfiguration和IConfigurationRoot是对键值对的抽象
- IConfigurationBuilder用于构建IConfiguration和IConfigurationRoot
- IConfigurationSource是对数据源的抽象
- IConfigurationProvider将不同来源的IConfigurationSource 转为统一的模型
- IOptions方便将不同的配置节点(Path)映射为对应的强类型对象
- IConfigurationBuilder添加多个数据源(IConfigurationSource)后,如果key重名,则以最后一个配置为准(覆盖前面)
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