ConfigurationManager.AppSettings does not work with the App.config file created programmatically

Question

I came across something interesting. I am trying to make a quick console application for our clients to run some connection strings for some of my programs. This is a "quick application" for customers, I want it to be "proof of an idiot."

One of the main features of the application is to recreate the default configuration file if it does not find it.

 if (!File.Exists("./App.config"))
        {
            Console.WriteLine("Config file is missing. Creating a new one now..");
            //file doesn't exist, let create one.
            var doc = new XDocument(
                new XDeclaration("1.0", "UTF-16", null)
                ,new XElement("configuration"
                    , new XElement("startup"
                        , new XElement("supportedRuntime", new XAttribute("version", "v4.0")
                            , new XAttribute("sku", ".NETFramework,Version=v4.5")))
                , new XElement("appSettings"
                    , new XElement("add", new XAttribute("key", "targetDatabaseName"), new XAttribute("value", ""))
                    , new XElement("add", new XAttribute("key", "applicationServer"), new XAttribute("value", ""))
                    , new XElement("add", new XAttribute("key", "sqlServer"), new XAttribute("value", ""))
                    , new XElement("add", new XAttribute("key", "applicationServerPort"), new XAttribute("value", ""))
                    , new XElement("add", new XAttribute("key", "customSearchPath"), new XAttribute("value", "")))));


            using (var sw = new StringWriter())
            {
                using (var xw = XmlWriter.Create(sw))
                {
                    doc.Save(xw);
                    xw.Close();
                }

                doc.Save("./App.config");
                sw.Close();

            }

        }  

During testing, I noticed that if the original App.config file is deleted and recreated using the application, all lines ConfigurationManager.AppSettingsstop functioning correctly. They always return null values ​​for each key, even if I manually change the values ​​in the restored configuration file.

, , exe?

app.config?

, , , , .

 _targetDatabaseName = ConfigurationManager.AppSettings["targetDatabaseName"];
        _applicationServer = ConfigurationManager.AppSettings["applicationServer"];
        _sqlServer = ConfigurationManager.AppSettings["sqlServer"];
        _applicationServerPort = ConfigurationManager.AppSettings["applicationServerPort"];

        var emptyKeys = new List<string>();

        if (string.IsNullOrEmpty(_targetDatabaseName))
            emptyKeys.Add("targetDatabaseName");

        if(string.IsNullOrEmpty(_applicationServer))
            emptyKeys.Add("applicationServer");

        if(string.IsNullOrEmpty(_sqlServer))
            emptyKeys.Add("sqlServer");

        if(string.IsNullOrEmpty(_applicationServerPort))
            emptyKeys.Add("applicationServerPort");

        if (emptyKeys.Count > 0)
        {
            Console.WriteLine("You are missing one of the following required keys "
            + string.Join(",", emptyKeys) +". Press"
                + " a key to exit the application.");

            Console.ReadKey();
            Environment.Exit(0);
        }  

,

<?xml version="1.0" encoding="utf-16"?>
<configuration>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <appSettings>
    <add key="targetDatabaseName" value="" />
    <add key="applicationServer" value="" />
    <add key="sqlServer" value="" />
    <add key="applicationServerPort" value="" />
    <add key="customSearchPath" value="" />
  </appSettings>
</configuration>

Answer 1

2 .

• , , , , :

  ConfigurationManager.RefreshSection( "AppSettings" )

MSDN: https://msdn.microsoft.com/en-us/library/system.configuration.configurationmanager(v=vs.110).aspx