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c# - ILogger 通过 Azure Function 2.x 的 Http 触发函数的构造函数注入

问题描述

ILogger可以注入函数参数，如Token下面的方法。

但是，将其注入构造函数参数时发生以下错误log。

[07/03/2019 17:15:17] 执行“令牌”（失败，Id=4e22b21f-97f0-4ab4-8f51-8651b 09aedc8）[07/03/2019 17:15:17] Microsoft.Extensions.DependencyInjection。抽象：尝试激活“功能”时，无法解析“Microsoft.Extensions.Logging.ILogger”类型的服务。

ILogger可以注入Token下面的函数参数。但是上面的错误是在注入到构造函数参数时发生的log。

public class Functions
{
    private HttpClient _httpClient;
    private IAppSettings _appSettings;
    private ILogger _log;

    public Functions(HttpClient httpClient, IAppSettings appSettings  //working for these two
      , ILogger log  //not working, errors
    )
    {

        _log = log;
    }

    [FunctionName("Token")]
    public async Task<IActionResult> Token(
        [HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "Token")]
        HttpRequest httpRequest,
        ILogger log)
    {

    }
}

下面的依赖注入

[assembly: WebJobsStartup(typeof(Startup))]
namespace MyApp
{
    public class Startup : IWebJobsStartup
    {
        public void Configure(IWebJobsBuilder builder)
        {
            builder.Services.AddHttpClient();
            builder.Services.AddTransient<IAppSettings, AppSettings>();     
             //builder.Services.AddLogging();  //not working
           //builder.Services.AddSingleton<ILogger>() //not working
        }
}

视觉工作室 2017

标签： c#azureazure-functions

解决方案

我也有这个问题。我可以通过调用来修复它AddLogging()：

[assembly: WebJobsStartup(typeof(Startup))]
namespace MyApp
{
    public class Startup : IWebJobsStartup
    {
        public void Configure(IWebJobsBuilder builder)
        {
            builder.Services.AddHttpClient();
            builder.Services.AddTransient<IAppSettings, AppSettings>();     
            builder.Services.AddLogging();
        }
}

然后，在 Azure 函数中，我必须通过 aILoggerFactory而不是 aILogger并从以下位置获取ILogger实例loggerFactory：

public class Functions
{
    private HttpClient _httpClient;
    private IAppSettings _appSettings;
    private ILogger _log;

    public Functions(HttpClient httpClient, IAppSettings appSettings, ILoggerFactory loggerFactory)
    {
        _log = loggerFactory.CreateLogger<Functions>();
    }

    [FunctionName("Token")]
    public async Task<IActionResult> Token(
        [HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "Token")]
        HttpRequest httpRequest)
    {
           // No need to keep getting the ILogger from the Run method anymore :)
    }
}

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