[C#]-Web.Config ayarını bir çırpıda değiştirmek

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            System.Configuration.Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
 
            System.Configuration.KeyValueConfigurationElement setting = config.AppSettings.Settings["MyValue"];
 
            if (null != setting)
            {
                textboxValue.Text = setting.Value;
            }
        }
    }
 

    protected void Button3_Click(object sender, EventArgs e)
    {
        try
        {
            System.Configuration.Configuration config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
 
            System.Configuration.KeyValueConfigurationElement setting = config.AppSettings.Settings["MyValue"];
 
            if (null != setting)
            {
                config.AppSettings.Settings["MyValue"].Value = textboxValue.Text;
            }
            else
            {
                config.AppSettings.Settings.Add("MyValue", textboxValue.Text);
            }
 
            config.Save();
            Label1.Text = "Değişiklik kayıt edildi.";
        }
        catch (System.Exception exc)
        {
            Label1.Text = (exc.Message + "<br />" + exc.StackTrace).Replace("\n", "<br />");
        }
    }