Question

我想在NET Core 2.2的运行时更改放置在appsettings.json文件中的连接字符串。

所以我的工作是：

在运行时更改appsettings.json中的连接字符串
重新加载Configuration类以获取修改后的连接字符串
刷新所有数据上下文以使用新的连接字符串

我认为步骤1.可以，我使用此代码，appsettings.json成功更改：

    public static void ChangeConnectionStringsInAppSettings(eConnectionStringType cstrType, string value)
    {
        var d = AppDomain.CurrentDomain.BaseDirectory;

        ChangeSettingsFile(Path.Combine(d, "appsettings.json"), cstrType, value);
        ChangeSettingsFile(Path.Combine(d, "appsettings.Development.json"), cstrType, value);
        ChangeSettingsFile(Path.Combine(d, "appsettings.Production.json"), cstrType, value);
    }

    private static void ChangeSettingsFile(string appSettingsJsonFilePath, eConnectionStringType cstrType, string value)
    {
        if (System.IO.File.Exists(appSettingsJsonFilePath))
        {
            var json = System.IO.File.ReadAllText(appSettingsJsonFilePath);
            dynamic jsonObj = Newtonsoft.Json.JsonConvert.DeserializeObject<Newtonsoft.Json.Linq.JObject>(json);

            if (cstrType == eConnectionStringType.Identity)
            {
                jsonObj["ConnectionStrings"]["IdentityConnection"] = value;
            }
            else if (cstrType == eConnectionStringType.Data)
            {
                jsonObj["ConnectionStrings"]["DefaultConnection"] = value;
            }

            string output = Newtonsoft.Json.JsonConvert.SerializeObject(jsonObj, Newtonsoft.Json.Formatting.Indented);

            System.IO.File.WriteAllText(appSettingsJsonFilePath, output);
        }
    }

使用setp 2和3，我遇到了问题。我尝试使用DI使IOptionsMonitor工作，但它始终显示旧值：

public class Startup
{

    public class ConnectionStrings
    {
        public string IdentityConnection { get; set; }
    }

    public void ConfigureServices(IServiceCollection services)

        // ...
        services.Configure<ConnectionStrings>(Configuration.GetSection("ConnectionStrings"));
        // ...
    }
}

控制器：

 public RolesController(
           AuthContext ACTX
         , MySiteContext CTX
         , UserManager<ApplicationUser> userManager
         , RoleManager<ApplicationRole> roleManager
         , IConfiguration configuration
         , IStringLocalizer localizer
         , My my
         , IRolesRepository repo
         , IOptionsMonitor<ConnectionStrings> options)
         : base(ACTX, CTX, userManager, roleManager, configuration, localizer, my, repo)
        {
            var _myValues = options.CurrentValue;
        }

        [UseAjax]
        [UseTelerik]
        [UseClientSideValidation]
        public IActionResult Index()
        {
            ChangeConnectionStringsInAppSettings(eConnectionStringType.Identity, "old");
            this.CheckDatabase();

            return View(new ApplicationRoleDto());
        }

        [UseAjax]
        [UseTelerik]
        [UseClientSideValidation]
        public IActionResult Index2()
        {
            ChangeConnectionStringsInAppSettings(eConnectionStringType.Identity, "new");
            this.CheckDatabase();

            return View("Index",new ApplicationRoleDto());
        }

我要停在这一步。新值未加载，成功后，我需要为所有datacontext设置新的connetiontion字符串。

能帮我吗？谢谢！

更改.NET Core配置运行时并重新加载

0 个答案: