c# program.exe.configuration

 When you need save and read some parameters which related about your settings or something else;

1. If your project does not have a "App.config" file; to make new one, right click  your project and "Add->New Item->App Configuration File".

2. Open "App.Config" file and view your file like that;

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System">
      <section name="DevExpress.LookAndFeel.Design.AppSettings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
    </sectionGroup>
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8"/>
  </startup>
	<appSettings>
		<add key="deviceModel" value="0" />
	</appSettings>
</configuration>

This is a code snippet for read value and change and save procedure;

var appSettings=ConfigurationManager.AppSettings;
if (appSettings["deviceModel"].Length!=0)
{
    textBox1.Text = appSettings["deviceModel"].ToString();
}

int tempVal;
var configFile = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
var settings = configFile.AppSettings.Settings;
if (settings["deviceModel"] == null)
{
    settings.Add("deviceModel", "1");
}
else
{
    tempVal = int.Parse(settings["deviceModel"].Value);
    tempVal++;
    settings["deviceModel"].Value = tempVal.ToString();
}
configFile.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection(configFile.AppSettings.SectionInformation.Name);