How to Write to app.config in setup project and use it in the program

Question

• I have created a Installhelper.cs which is inhered from the Installer.
• Override the Install() method by using this piece of code(A).

These values that are inserted to the app.config are not available in the [projectName].exe.config file that is created after installation. I have already added a section as shown below in the app.config manually (B)

data is passed to the installer class but the data is not written to the app.config fields. They remain same in the created configuration file during installation.

Any Help is greatly appreciated. I have spent almost a day on this.

Code A:

[RunInstaller(true)]
public partial class Installation : System.Configuration.Install.Installer
{
    public Installation()
    {
        InitializeComponent();
    }

    public override void Install(IDictionary stateSaver)
    {
        //base.Install(stateSaver);

        try
        {
            // In order to get the value from the textBox named 'EDITA1' I needed to add the line:
            // '/PathValue = [EDITA1]' to the CustomActionData property of the CustomAction We added. 

            string userName = Context.Parameters["userName"];
            string password = Context.Parameters["password"];
            string folderPath = Context.Parameters["path"];

            MessageBox.Show(userName);
            MessageBox.Show(password);
            MessageBox.Show(folderPath);

            Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
           //config.AppSettings.Settings.Add("userName", userName);
           //config.AppSettings.Settings.Add("password", password);
           //config.AppSettings.Settings.Add("foderPath", folderPath);





            config.AppSettings.Settings["userName"].Value = userName;
            config.AppSettings.Settings["password"].Value = password;
            config.AppSettings.Settings["foderPath"].Value = folderPath;
            config.Save(ConfigurationSaveMode.Full);
            ConfigurationManager.RefreshSection("appSettings");




        }
        catch (FormatException e)
        {
            string s = e.Message;
            throw e;
        }
    }
}

Added section in the app config is Code B:

<appSettings>
<add key="userName" value="" />
<add key="password" value="" />
<add key="foderPath" value="" />
</appSettings>

Answer 1

The problem of this coding was this line

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

It does not give the path where the config file relies during the installation.So it has to be changed in to

string path = Path.Combine(new DirectoryInfo(Context.Parameters["assemblypath"].ToString()).Parent.FullName, "[project name].exe")

    Configuration config = ConfigurationManager.OpenExeConfiguration(path);

Now its working. :)