如何在Core 2.0中的ConfigurationBuilder中设置SetBasePath

Question

如何在Core 2.0中的ConfigurationBuilder中设置基本路径.

我用Google搜索,发现这个问题,这个来自微软的文档,以及2.0文档在线,但他们似乎使用的版本Microsoft.Extension.Configuration从1.0.0-beta8.

我想读appsettings.json.在Core 2.0中有没有新的方法？

using System;
using System.IO;
using Microsoft.Extensions.Configuration;
namespace ConsoleApp2
{
    class Program
    {
        public static IConfigurationRoot Configuration { get; set; }

        static void Main(string[] args)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory()) // <== compile failing here
                .AddJsonFile("appsettings.json");

            Configuration = builder.Build();

            Console.WriteLine(Configuration.GetConnectionString("con"));
            Console.WriteLine("Press a key...");
            Console.ReadKey();
        }
    }
}

appsetting.json

{
  "ConnectionStrings": {
    "con": "connection string"
  }
}

更新: 除了添加Microsoft.Extensions.Configuration.FileExtensions如下图所示的设置我还需要添加Microsoft.Extensions.Configuration.Json得到AddJsonFile扩展.

Answer 1

该SetBasePath扩展方法中定义Config.FileExtensions.

您需要添加对Microsoft.Extensions.Configuration.FileExtensions包的引用.

要解决此问题AddJsonFile,请添加对Microsoft.Extensions.Configuration.Json包的引用.

Answer 2

我正在使用Visual Studio 2017 v15.5开发.NET Core 2控制台应用程序.正如其他人所说,在添加Microsoft.Extensions.Configuration后,我需要添加Microsoft.Extensions.Configuration.Json以使AddJsonFile()调用工作.这也使SetBasePath()呼叫工作; 所以我不需要添加Configuration.FileExtensions.(我的代码在有和没有它的情况下编译和运行.)

我也打电话给AddEnvironmentVariables()我,我需要添加Configuration.EnvironmentVariables.我的代码如下:

  var builder = new ConfigurationBuilder()
                    .SetBasePath(Directory.GetCurrentDirectory()) // requires Microsoft.Extensions.Configuration.Json
                    .AddJsonFile("appsettings.json") // requires Microsoft.Extensions.Configuration.Json
                    .AddEnvironmentVariables(); // requires Microsoft.Extensions.Configuration.EnvironmentVariables
  Configuration = builder.Build();

有趣的是,using我需要的唯一声明是using Microsoft.Extensions.Configuration.

Answer 3

使用'Microsoft.Extensions.Configuration'和'Microsoft.Extensions.Configuration.Json'这将解决问题.

https://www.nuget.org/packages/Microsoft.Extensions.Configuration/ https://www.nuget.org/packages/Microsoft.Extensions.Configuration.Json/

这是示例'ConnectionFactory'

using System.Data;
using System.Data.SqlClient;
using Microsoft.Extensions.Configuration;
using System.IO;

namespace DataAccess.Infrastructure
{
 public class ConnectionFactory : IConnectionFactory
 {
    public ConnectionFactory()
    {
        var builder = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json");
        Configuration = builder.Build();
    }


    public IConfigurationRoot Configuration { get; }
    public IDbConnection GetConnection
    {
        get
        {
            var connectionString = Configuration.GetConnectionString("DefaultConnection");
            var conn = new SqlConnection(connectionString);
            conn.Open();
            return conn;
        }
    }

    #region IDisposable Support
    private bool disposedValue = false; // To detect redundant calls

    protected virtual void Dispose(bool disposing)
    {
        if (!disposedValue)
        {
            if (disposing)
            {
                // TODO: dispose managed state (managed objects).
            }


            // TODO: free unmanaged resources (unmanaged objects) and override a finalizer below.
            // TODO: set large fields to null.

            disposedValue = true;
        }
    }

    // TODO: override a finalizer only if Dispose(bool disposing) above has code to free unmanaged resources.
    // ~ConnectionFactory() {
    //   // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
    //   Dispose(false);
    // }

    // This code added to correctly implement the disposable pattern.
    public void Dispose()
    {
        // Do not change this code. Put cleanup code in Dispose(bool disposing) above.
        Dispose(true);
        // TODO: uncomment the following line if the finalizer is overridden above.
        // GC.SuppressFinalize(this);
    }
    #endregion
} }