As Eli Arbel already said you can’t modify values written in web.config from your application code. You can only do this manually but then the application will restart and this is something you don’t want.
Here is a simple class you can use to store values and make them easy to read and modify. Just update the code to suite your needs if you’re reading from XML or database and depending on whether you want to permanently store modified values.
public class Config
{
public int SomeSetting
{
get
{
if (HttpContext.Current.Application["SomeSetting"] == null)
{
//this is where you set the default value
HttpContext.Current.Application["SomeSetting"] = 4;
}
return Convert.ToInt32(HttpContext.Current.Application["SomeSetting"]);
}
set
{
//If needed add code that stores this value permanently in XML file or database or some other place
HttpContext.Current.Application["SomeSetting"] = value;
}
}
public DateTime SomeOtherSetting
{
get
{
if (HttpContext.Current.Application["SomeOtherSetting"] == null)
{
//this is where you set the default value
HttpContext.Current.Application["SomeOtherSetting"] = DateTime.Now;
}
return Convert.ToDateTime(HttpContext.Current.Application["SomeOtherSetting"]);
}
set
{
//If needed add code that stores this value permanently in XML file or database or some other place
HttpContext.Current.Application["SomeOtherSetting"] = value;
}
}
}