我想读取 Startup 类中 host.json 中定义的连接字符串。问题是运行时 IConfiguration 始终为 null !
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net8.0</TargetFramework>
<AzureFunctionsVersion>v4</AzureFunctionsVersion>
<OutputType>Exe</OutputType>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<FrameworkReference Include="Microsoft.AspNetCore.App" />
<PackageReference Include="Azure.Storage.Queues" Version="12.18.0" />
<PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker" Version="1.20.1" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http" Version="3.1.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore" Version="1.2.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.Sdk" Version="1.16.4" />
<PackageReference Include="Microsoft.ApplicationInsights.WorkerService" Version="2.22.0" />
<PackageReference Include="Microsoft.Azure.Functions.Worker.ApplicationInsights" Version="1.1.0" />
<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
<PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
</ItemGroup>
<ItemGroup>
<None Update="host.json">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>
<None Update="local.settings.json">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
<CopyToPublishDirectory>Never</CopyToPublishDirectory>
</None>
<None Update="Properties\launchSettings.json">
<CopyToOutputDirectory>Always</CopyToOutputDirectory>
</None>
</ItemGroup>
<ItemGroup>
<Using Include="System.Threading.ExecutionContext" Alias="ExecutionContext" />
</ItemGroup>
<ItemGroup>
<Compile Update="Startup.cs">
<CopyToOutputDirectory>Never</CopyToOutputDirectory>
</Compile>
</ItemGroup>
</Project>
这是Function1.csproj
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Configuration;
[assembly: FunctionsStartup(typeof(MyNamespace.Startup))]
namespace MyNamespace
{
public class Startup : FunctionsStartup
{
public override void Configure(IFunctionsHostBuilder builder)
{
var configuration = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("host.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables().Build();
IConfiguration conf = configuration;
builder.Services.AddSingleton(conf);
builder.Services.AddHttpClient();
}
}
}
这是我为 IConfiguration 的依赖注入定义的启动类!
using FirstFunction.dto;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Globalization;
using System.Text;
using Azure.Storage.Queues;
using Azure.Storage.Queues.Models;
using Microsoft.Extensions.Configuration;
using System.Reflection;
namespace FirstFunction
{
public class Function1
{
private readonly ILogger<Function1> _logger;
private readonly IConfiguration _configuration;
private readonly HttpClient _httpClient;
public Function1(ILogger<Function1> logger)
{
_logger = logger;
}
public Function1(ILogger<Function1> logger, IConfiguration configuration, HttpClient httpClient) : this(logger)
{
_configuration = configuration;
_httpClient = httpClient;
}
[Function("Function1")]
public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
{
#region Catch Error
string requestBody = string.Empty;
try
{
requestBody = await new StreamReader(req.Body).ReadToEndAsync();
}
catch (Exception ex)
{
_logger.LogError($"Error reading request body: {ex.Message}");
return new StatusCodeResult(StatusCodes.Status500InternalServerError);
}
#endregion
string myConnectionString = _configuration["ConnectionStrings:QUEUE_CONNECTION_STRING"];
return new OkObjectResult("Data was sent to backend");
}
}
}
这是我的天蓝色函数方法。代码已缩短
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
var host = new HostBuilder()
.ConfigureFunctionsWebApplication()
.ConfigureServices(services =>
{
services.AddApplicationInsightsTelemetryWorkerService();
services.ConfigureFunctionsApplicationInsights();
})
.Build();
host.Run();
这是生成的名为 Programm.cs
错误消息不是那么准确,因为我让它滑动了!
谢谢您的帮助!
在隔离模型中,不使用启动,要从
host.json
获取价值,请使用下面的代码,我已经遵循了SO-Thread:
程序.cs:
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
var host = new HostBuilder()
.ConfigureFunctionsWebApplication()
.ConfigureServices(services =>
{
services.AddApplicationInsightsTelemetryWorkerService();
services.ConfigureFunctionsApplicationInsights();
})
.ConfigureAppConfiguration((context, config) =>
{
config.SetBasePath(context.HostingEnvironment.ContentRootPath)
.AddJsonFile("host.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables();
})
.Build();
host.Run();
函数1.cs:
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
namespace FunctionApp200
{
public class Function1
{
private readonly ILogger<Function1> _logger;
private readonly IConfiguration ri_con;
public Function1(ILogger<Function1> logger, IConfiguration config)
{
_logger = logger;
ri_con = config;
}a
[Function("Function1")]
public IActionResult Run([HttpTrigger(AuthorizationLevel.Function, "get", "post")] HttpRequest req)
{
_logger.LogInformation("C# HTTP trigger function processed a request.");
var rith = ri_con["Value"];
Console.WriteLine(rith);
return new OkObjectResult($"Hello Rithwik, value is {rith}");
}
}
}
主机.json:
{
"version": "2.0",
"logging": {
"applicationInsights": {
"samplingSettings": {
"isEnabled": true,
"excludedTypes": "Request"
},
"enableLiveMetricsFilters": true
}
},
"Value": "Rithwik"
}
输出: