.NET Core 3.x 控制台应用调用 IConfiguration 和 依赖注入

IConfiguration

IConfiguration有两个包

Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration.Json

具体使用

先创建 appsettings.json，注意两个选项

这个 Json 文件内容

{
  "RabbitMQ": {
    "HostName": "192.168.0.151",
    "Port": "5672",
    "Administrator": {
      "Username": "administrator",
      "Password": "123456"
    }
  }
}

然后是创建对象，两种方法
方法一

private static IConfiguration _configuration = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json").Build();

方法二

private static IConfiguration _configuration = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();

完整代码

class Program
{
    private static IConfiguration _configuration = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json").Build();

    static void Main(string[] args)
    {
        Console.WriteLine(Program._configuration["RabbitMQ:HostName"]);
    }
}

运行结果

依赖注入

添加一个包

Microsoft.Extensions.DependencyInjection

这个配置就很简单了，根据ASP.NET Core的写

IServiceCollection services = new ServiceCollection();

举个例子，IConfiguration 的依赖注入

IServiceCollection services = new ServiceCollection();
services.AddSingleton<IConfiguration>(serviceProvider =>
{
    IConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
    configurationBuilder.AddJsonFile("appsettings.json");
    return configurationBuilder.Build();
});

创建对象

IConfiguration configuration = services.BuildServiceProvider().GetService<IConfiguration>();
Console.WriteLine(configuration["RabbitMQ:HostName"]);

运行结果

配置普通类

这个就跟ASP.NET Core一样了

比如我有一个Test类，你也可以先写一个接口，再写一个类

public class Test
{
    private readonly IConfiguration _configuration;

    public Test(IConfiguration configuration)
    {
        this._configuration = configuration;
    }

    public void Foo()
    {
        Console.WriteLine(this._configuration["RabbitMQ:HostName"]);
    }
}

配置只有一句

services.AddSingleton<Test>();

完整代码

static void Main(string[] args)
{
    IServiceCollection services = new ServiceCollection();
    services.AddSingleton<IConfiguration>(serviceProvider =>
    {
        IConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
        configurationBuilder.AddJsonFile("appsettings.json");
        return configurationBuilder.Build();
    });

    services.AddSingleton<Test>();
    Test t = services.BuildServiceProvider().GetService<Test>();
    t.Foo();
}

运行结果

如果需要在其它类中调用容器，只需要将IServiceProvider serviceProvider作为参数传递即可，或者作为静态字段写类里面，单例模式也行

当然，也可以用AutoFac，C# 自带的容器也可以，使用方式基本一致

.NET Core 3.x 控制台应用调用 IConfiguration 和 依赖注入 结束