Programatically Modifying and Saving AppSetting value in Root Level Web.Config using ASP.NET C#

In this blog we are going to see, How to Modify the AppSettings value and Save it.

Root Level Web.Config

<appSettings>
<add key="AppKey" value="AppValue"/>
</appSettings>

Code Snippet

using System;
using System.Configuration;
using System.Web.Configuration;

namespace SampleApplication.WebConfig
{
public partial class webConfigFile : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)

{
//Helps to open the Root level web.config file.
Configuration webConfigApp = WebConfigurationManager.OpenWebConfiguration("~");

//Modifying the AppKey from AppValue to AppValue1
webConfigApp.AppSettings.Settings["AppKey"].Value = "AppValue1";

//Save the Modified settings of AppSettings.
webConfigApp.Save();
}
}
}

Output of Root Level Web.Config:

<appSettings>
<add key="AppKey" value="AppValue1"/>
</appSettings>