最近我还需要从appsettings中读取一个简单的字符串数组。Json文件(以及其他类似的. Json配置文件)。

对于我的方法，我创建了一个简单的扩展方法:

public static class IConfigurationRootExtensions
{
    public static string[] GetArray(this IConfigurationRoot configuration, string key)
    {
        var collection = new List<string>();
        var children = configuration.GetSection(key)?.GetChildren();
        if (children != null)
        {
            foreach (var child in children) collection.Add(child.Value);
        }
        return collection.ToArray();
    }
}

原始海报的.json文件如下所示:

{
      "MyArray": [
          "str1",
          "str2",
          "str3"
      ]
}

使用上面的扩展方法，它使读取这个数组成为一个非常简单的一行事务，如下面的例子所示:

var configuration = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();
string[] values = configuration.GetArray("MyArray");

在运行时，在值上设置一个'QuickWatch'的断点，以验证我们已经成功地将.json配置文件中的值读入一个字符串数组:

这对我很管用; 创建json文件:

{
    "keyGroups": [
        {
            "Name": "group1",
            "keys": [
                "user3",
                "user4"
            ]
        },
        {
            "Name": "feature2And3",
            "keys": [
                "user3",
                "user4"
            ]
        },
        {
            "Name": "feature5Group",
            "keys": [
                "user5"
            ]
        }
    ]
}

然后，定义一些映射类:

public class KeyGroup
{
    public string name { get; set; }
    public List<String> keys { get; set; }
}

nuget packages:

Microsoft.Extentions.Configuration.Binder 3.1.3
Microsoft.Extentions.Configuration 3.1.3
Microsoft.Extentions.Configuration.json 3.1.3

然后加载它:

using Microsoft.Extensions.Configuration;
using System.Linq;
using System.Collections.Generic;

ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();

configurationBuilder.AddJsonFile("keygroup.json", optional: true, reloadOnChange: true);

IConfigurationRoot config = configurationBuilder.Build();

var sectionKeyGroups = 
config.GetSection("keyGroups");
List<KeyGroup> keyGroups = 
sectionKeyGroups.Get<List<KeyGroup>>();

Dictionary<String, KeyGroup> dict = 
            keyGroups = keyGroups.ToDictionary(kg => kg.name, kg => kg);

在IOptions不起作用后，我发现这更简单，序列化时要做的事情也少得多。

//appsettings.json
"DatabaseModelCreationOptions": {
    "Users": [
      {
        "Id": "1",
        "UserName": "adminuser",
        "Email": "youremail@myemail.com",
        "Password": "!Ch4",
        "Player": "Admin",
        "PlayerInitials": "ADMIN",
        "ApiKey": "40753ey"
      }
    ],   
    "UserRoles": [
      {
        "Id": "af9986df",
        "Name": "Admin",
        "ConcurrencyStamp": "ddd53170"
      },
      {
        "Id": "03b82b0e",
        "Name": "Manager",
        "ConcurrencyStamp": "65da3f89"
      }
    ]
}

我需要的类，我不需要给你们看嵌套的类属性，你们可以在上面看到。

public class DatabaseModelCreationOptions
{
    public IEnumerable<User>? Users { get; set; }
    public IEnumerable<UserRole>? UserRoles { get; set; }
}

然后调用GetSection("")。得到

var dbOptions = configuration.GetSection("DatabaseModelCreationOptions")
    .Get<DatabaseModelCreationOptions>();

.Net Core 7.x中处理对象的不同方法

在appsettings.json:

{
      "People": [
          { "FirstName": "Glen", "LastName": "Johnson", "Age": 30 },
          { "FirstName": "Matt", "LastName": "Smith", "Age": 40 },
          { "FirstName": "Fred", "LastName": "Williams", "Age": 50 }
      ]
}

Person类:

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
}

在代码中:

var appConfig = App.Current.AppConfiguration;   // Or could be passed in through DI
var children = appConfig.GetSection("People")
    .GetChildren()
    .ToList();

var people = new List<Person>();
foreach (var child in children)
{
    var rec = new Person
    {
        FirstName = appConfig[$"{child.Path}:FirstName"],
        LastName = appConfig[$"{child.Path}:LastName"],
        Age = int.Parse(appConfig[$"{child.Path}:Age"]),
    };
    people.Add(rec);
}

设置。json文件:

{
    "AppSetting": {
        "ProfileDirectory": "C:/Users/",
        "Database": {
            "Port": 7002
        },
        "Backend": {
            "RunAsAdmin": true,
            "InstallAsService": true,
            "Urls": [
                "http://127.0.0.1:8000"
            ],
            "Port": 8000,
            "ServiceName": "xxxxx"
        }
    }
}

code

代码:

public static IConfigurationRoot GetConfigurationFromArgs(string[] args, string cfgDir)
{
    var builder = new ConfigurationBuilder()
            .SetBasePath(cfgDir)
            .AddCommandLine(args ?? new string[0]) // null  in UnitTest null will cause exception
            .AddJsonFile(Path.Combine(cfgDir, "setting.json"), optional: true, reloadOnChange: true)
            .AddEnvironmentVariables()
        // .AddInMemoryollection(configDictionary)
        ;
    var config = builder.Build();
    return config;
}

你可以使用services.AddOptions<AppSettingOption>("AppSetting")或者直接从iconfigationroot对象获取Object。

var cfg = GetConfigurationFromArgs(args, appDataDirectory);
cfg.GetSection("AppSetting").Get<AppSettingOption>()

输出:

{App.AppSettingOption}
    Backend: {App.BackendOption}
    Database: {App.DatabaseOption}
    ProfileDirectory: "C:/Users/"

从appsettings.json中获取所有section的所有值

        public static string[] Sections = { "LogDirectory", "Application", "Email" };
        Dictionary<string, string> sectionDictionary = new Dictionary<string, string>();

        List<string> sectionNames = new List<string>(Sections);
        
        sectionNames.ForEach(section =>
        {
            List<KeyValuePair<string, string>> sectionValues = configuration.GetSection(section)
                    .AsEnumerable()
                    .Where(p => p.Value != null)
                    .ToList();
            foreach (var subSection in sectionValues)
            {
                sectionDictionary.Add(subSection.Key, subSection.Value);
            }
        });
        return sectionDictionary;