IOptions的.NET Core 3 Worker服务依赖项注入配置

问题描述

我对工人服务部的直接投资有疑问，下面回答了另一篇文章。

i have a question about DI on Worker Service that answered another post below.

如果我想添加一些帮助程序类并进行了如下注册。
如何使用该选项注入。
因为我想我错过了一些东西...

what if i want to add some helper class and registered as below.How can i use that option injection.because i think, i missed something...

public static IHostBuilder CreateHostBuilder(string[] args)
    {
        return Host.CreateDefaultBuilder(args)

            .ConfigureAppConfiguration((hostContext, config) =>
            {
                // Configure the app here.
                config
                .SetBasePath(Environment.CurrentDirectory)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", optional: true);

                config.AddEnvironmentVariables();

                Configuration = config.Build();

            })

            .ConfigureServices((hostContext, services) =>
            {

                services.AddOptions();

                services.Configure<MySettings>(Configuration.GetSection("MySettings"));


                services.AddSingleton<RedisHelper>();

                services.AddHostedService<Worker>();

            });
    }

RedisHelper类的构造函数为Worker。

RedisHelper class has a constructor like this as Worker.

public static MySettings _configuration { get; set; }

public RedisHelper(IOptions<MySettings> configuration)
{
    if (configuration != null)
        _configuration = configuration.Value;
}

推荐答案

无需构建配置你自己您可以通过 hostContext

No need to build the config yourself. You can access it in the ConfigureServices via the hostContext

public static IHostBuilder CreateHostBuilder(string[] args) {
    return Host.CreateDefaultBuilder(args)
        .ConfigureAppConfiguration((hostContext, config) => {
            // Configure the app here.
            config
                .SetBasePath(Environment.CurrentDirectory)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", optional: true);

            config.AddEnvironmentVariables();
        })
        .ConfigureServices((hostContext, services) => {

            services.AddOptions();

            services.Configure<MySettings>(hostContext.Configuration.GetSection("MySettings"));
            services.AddSingleton<RedisHelper>();
            services.AddHostedService<Worker>();
        });
}

现在，只需将选项注入所需的帮助器类中

Now it is just a matter of injecting the options into the desired helper class

//...

public RedisHelper(IOptions<MySettings> configuration) {
    if (configuration != null)
        _configuration = configuration.Value;
}

//...

服务

public Worker(RedisHelper helper) {
    this.helper = helper;
}

这篇关于IOptions的.NET Core 3 Worker服务依赖项注入配置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！