我尝试创建一个 .NET 6 控制台应用程序,但无法读取我的 appsettings.json 文件。在网络应用程序中,我可以使用这个...
var builder = WebApplication.CreateBuilder(args);
但是我会在控制台应用程序中使用什么?尝试将其添加到 program.cs 时出现此错误。
"The name 'WebApplication' does not exist in the current context"
在您的应用程序中添加这两个 nuget 包
Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration.Json
然后你可以使用
ConfigurationBuilder
来使用appsettings.json
文件
var configuration = new ConfigurationBuilder()
.AddJsonFile($"appsettings.json");
var config = configuration.Build();
var connectionString = config.GetConnectionString("ConnectionString");
文档链接:https://learn.microsoft.com/en-us/dotnet/core/extensions/configuration
需要Nuget包来做到这一点:
<PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="6.0.0" />
<PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="6.0.0" />
<PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="6.0.0" />
使用 Microsoft.Extensions.Configuration;
// Build a config object, using env vars and JSON providers.
IConfiguration config = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
.AddEnvironmentVariables()
.Build();
// Get values from the config, given their key and their target type.
Settings settings = config.GetRequiredSection("Settings").Get<Settings>();
// Write the values to the console.
Console.WriteLine($"KeyOne = {settings.KeyOne}");
Console.WriteLine($"KeyTwo = {settings.KeyTwo}");
Console.WriteLine($"KeyThree:Message = {settings.KeyThree.Message}");
// Application code which might rely on the config could start here.
// This will output the following:
// KeyOne = 1
// KeyTwo = True
// KeyThree:Message = Oh, that's nice...
JSON 文件 (appsettings.json)
{
"Settings": {
"KeyOne": 1,
"KeyTwo": true,
"KeyThree": {
"Message": "Oh, that's nice..."
}
}
}
UPD:我检查了方法,它有效; 我的代码:
// See https://aka.ms/new-console-template for more information
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
Console.WriteLine("Hello, World!");
ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
IConfiguration c = configurationBuilder.AddJsonFile("appsettings.json").AddEnvironmentVariables().Build();
var k = c.GetRequiredSection("Settings").Get<Settings>().KeyOne;
var n = 1;
public class NestedSettings
{
public string Message { get; set; } = null!;
}
public class Settings
{
public int KeyOne { get; set; }
public bool KeyTwo { get; set; }
public NestedSettings KeyThree { get; set; } = null!;
}
使用 .NET 6 控制台应用程序,尝试:
using IHost host = Host.CreateDefaultBuilder(args).Build();
IConfiguration config = host.Services.GetRequiredService<IConfiguration>();
string con= config.GetValue<string>("ConnectionStrings:conn1");
//OR
string connectionString = config["ConnectionStrings:conn1"];
Console.WriteLine($"Hello, World! {connectionString}");
appsettings.json(属性):(CopyToOutputDirectory = Always):
"ConnectionStrings": {
"conn1": "Server=localhost;Database=MyDatabase;Trusted_Connection=True",
}
在控制台应用程序中,我像这样添加
appsettings.json
和 user secrets
,您也可能有一个开发 json 文件。
internal class Program
{
internal static IConfigurationRoot Configuration;
public static void Main()
=> new Program().MainAsync().GetAwaiter().GetResult();
private async Task MainAsync()
{
var configurationBuilder = new ConfigurationBuilder();
configurationBuilder.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
configurationBuilder.AddUserSecrets(typeof(Program).GetTypeInfo().Assembly, optional: false);
Configuration = configurationBuilder.Build();
...
}
}
然后在任何类的控制台应用程序的其他地方,您可以像这样简单地调用它
var someSetting = Program.Configuration["SomeSetting"];
如果你想要一个强类型的类然后看到这个答案.net 核心控制台应用程序在 SO 上强类型配置
我更喜欢下面的代码,因为它会自动从项目目录中读取 appsettings.json 文件。注意
_.Configuration
我在配置DbContext时使用读取连接字符串。
var builder = Host.CreateDefaultBuilder(args)
.ConfigureServices(
(_, services) => services
.AddTransient<IService, Service>()
.AddDbContext<ApplicationDbContext>(options =>
options.UseNpgsql(
_.Configuration.GetConnectionString("DefaultConnection"),
b => b.MigrationsAssembly(typeof(ApplicationDbContext).Assembly.FullName)))
);
var host = builder.Build();
var dbContext = host.Services.GetRequiredService<ApplicationDbContext>();
我从这个链接把它放在一起:https://bjdejongblog.nl/net-core-6-dependency-injection-console-program/
安装以下软件包
Install-Package Microsoft.Extensions.Configuration.Json
Install-Package Microsoft.Extensions.Hosting
创建文件调用
appsettings.json
{
"AllowedHosts": "*",
"ConnectionStrings": {
"defaultConnection": "data source=.;initial catalog=ExchangeGatewayDb;integrated security=true;MultipleActiveResultSets=True;"
}
}
将此代码添加到
Programe.cs
var hostBuilder = new HostBuilder().ConfigureHostConfiguration(config =>
{
config.AddEnvironmentVariables();
if (args != null)
{
config.AddCommandLine(args);
}
}).ConfigureAppConfiguration((context, builder) =>
{
var env = context.HostingEnvironment;
builder.SetBasePath(AppContext.BaseDirectory)
.AddJsonFile("appsettings.json", optional: false)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true).AddEnvironmentVariables();
var configuration = builder.Build();
var connectionString = configuration["ConnectionStrings:defaultConnection"];
}).ConfigureServices(services =>
{
services.Configure<ConsoleLifetimeOptions>(opts => opts.SuppressStatusMessages = true);
//your code
});
var buildHost = hostBuilder.Build();
buildHost.Run();