CSharp C# - App.Config – Example of programmic change

CSharp C# - App.Config – Example of programmic change

Programmically change an App.Config file:

Note that this only changes in memory - I do not see any changes to the App.Config file.

To see an example where the file is actually modified go here.

TOC

Program.cs

Output

App.Config

Program.cs:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Configuration;  //Requires System.Configuration.dll

namespace TestAppConfigMod

{

   class Program

   {

       static void Main(string[] args)

       {

           string keyNow = "Browser";

           string valueNow = "Mozilla";

           /*

            * OUTPUT from the above:

            *  The App.Settings key "Browser" is now "Mozilla"

            *  Press enter to complete program.             

            */

           Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

           if (ConfigurationManager.AppSettings[keyNow] == null)

           {

               config.AppSettings.Settings.Add(keyNow, valueNow);

           }

           else

           {

               config.AppSettings.Settings[keyNow].Value = valueNow;

           }

           config.Save();

           ConfigurationManager.RefreshSection("appSettings");

           Console.WriteLine("The App.Settings key \"{0}\" is now \"{1}\"", keyNow, ConfigurationManager.AppSettings[keyNow]);

           Console.WriteLine("Press enter to complete program.");

           Console.ReadLine();

       }

   }

}

App.Config:

<?xml version="1.0" encoding="utf-8" ?>

<configuration>

 <startup>

   <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />

 </startup>

 <appSettings>

   <add key ="Browser" value="IE"/>

   <add key="myURL" value="https://mydomainA.com/" />

   <add key="CompanyName" value="TestCompanyA"/>

 </appSettings>

</configuration>