## On this page # Example 26 - C# Last update: 17.07.2025 # C# using System; using [ZOSAPI](namespace_z_o_s_a_p_i.xhtml); using [ZOSAPI.Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml); namespace CSharpStandaloneApplication4 { class Program { static void Main(string[] args) { // Find the installed version of OpticStudio bool isInitialized = ZOSAPI_NetHelper.ZOSAPI_Initializer.Initialize(); // Note -- uncomment the following line to use a custom initialization path //bool isInitialized = ZOSAPI\_NetHelper.ZOSAPI\_Initializer.Initialize(@"C:\\Program Files\\OpticStudio\\"); if (isInitialized) { LogInfo("Found OpticStudio at: " + ZOSAPI_NetHelper.ZOSAPI_Initializer.GetZemaxDirectory()); } else { HandleError("Failed to locate OpticStudio!"); return; } BeginStandaloneApplication(); } static void BeginStandaloneApplication() { // Create the initial connection class [ZOSAPI\_Connection](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml) TheConnection = new [ZOSAPI\_Connection](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml)(); // Define a Preferences File. // Preferences file is defined on the IZOSAPIConnection interface (prior to connecting to the API) // If no PreferencesFile is defined it will use the default OpticStudio.CFG file however changes will not persist between sessions. // If a PreferencesFile is defined, then any changes will save automatically. Console.WriteLine("===PreferencesFile==="); string cfgFile = @"C:\\Users\\Documents\\Zemax\\Configs\\OpticStudio.CFG"; if (System.IO.File.Exists(cfgFile)) { TheConnection.PreferencesFile = cfgFile; Console.WriteLine("PreferencesFile: " + TheConnection.[PreferencesFile](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml#a18dc1b1ef3fac28798acc2ecdedd3e08)); } else { Console.WriteLine("Default OpticStudio.CFG prefernces used"); } // Attempt to create a Standalone connection [IZOSAPI\_Application](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml) TheApplication = TheConnection.[CreateNewApplication](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml#aadc54af7d7415a765592acf23d3a08ef)(); if (TheApplication == null) { HandleError("An unknown connection error occurred!"); return; } // Check the connection status if (!TheApplication.[IsValidLicenseForAPI](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a5b8d6c216c668d13d6dcb870698c247f)) { HandleError("Failed to connect to OpticStudio: " + TheApplication.[LicenseStatus](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a95179eb8038b629caa12397723aacb3a)); return; } if (TheApplication.[Mode](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a8d2a89bafe9778c14f592276e5a5eb19) != [ZOSAPI\_Mode](namespace_z_o_s_a_p_i.xhtml#a254f5f6cb4ff37c2245b456b9bb79d2a).Server) { HandleError("User plugin was started in the wrong mode: expected Server, found " + TheApplication.[Mode](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a8d2a89bafe9778c14f592276e5a5eb19).ToString()); return; } [IOpticalSystem](interface_z_o_s_a_p_i_1_1_i_optical_system.xhtml) TheSystem = TheApplication.[PrimarySystem](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#aca8045fe84351622e0ee58814a2a3364); // Add your custom code here... // Define variables for OpticStudio Preferences [IPreferences](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml) Preference = TheApplication.[Preferences](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a2b0d83df3552a7647a57a22a9496f43d); [IPreferencesGeneral](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml) PrefG = Preference.[General](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml#a962ef89db42273aca29102b6fb812d4a); // Read and print the initial settings Console.WriteLine("\\n===Check Settings==="); Console.WriteLine("DateTimeFormat: " + PrefG.[DateTimeFormat](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a08c9851a5c9e95249e247964f4d8246c)); Console.WriteLine("Language: " + PrefG.[Language](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#acdb183b72e7c6d518ab2498266d96120)); Console.WriteLine("ZMXFileEncoding: " + PrefG.[ZMXFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a00b869844d613fba6402c2e08433eb7a)); Console.WriteLine("TXTFileEncoding: " + PrefG.[TXTFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a32c4bdb3c87442c8e25f1b3fff721c68)); Console.WriteLine("UseSessionFiles: " + PrefG.[UseSessionFiles](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a05297c825e3d5db4b61b39f312fd0e07)); Console.WriteLine("IncludeCalculatedDataInsession: " + PrefG.[IncludeCalculatedDataInSession](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a5dedeeb661115644cc06de1688cf5c95)); Console.WriteLine("UpdateMostRecentlyUsedList: " + PrefG.[UpdateMostRecentlyUsedList](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a2efa6ee6fe4db0f5cc839ab473462272)); Console.WriteLine("UserPreferences: " + PrefG.[UserPreferences](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#ac46784a53f375871f7050942ea3ef76b)); // Reset the settings to default Preference.[ResetToDefaults](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml#a46785d61c4607d6b571022ac4a47f208)(); // Set the settings PrefG.DateTimeFormat = [ZOSAPI](namespace_z_o_s_a_p_i.xhtml).[Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml).DateTimeType.DateTime; PrefG.Language = [ZOSAPI](namespace_z_o_s_a_p_i.xhtml).[Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml).LanguageType.English; PrefG.ZMXFileEncoding = [ZOSAPI](namespace_z_o_s_a_p_i.xhtml).[Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml).EncodingType.ANSI; PrefG.TXTFileEncoding = [ZOSAPI](namespace_z_o_s_a_p_i.xhtml).[Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml).EncodingType.ANSI; PrefG.UseSessionFiles = false; PrefG.IncludeCalculatedDataInSession = false; PrefG.UpdateMostRecentlyUsedList = false; PrefG.UserPreferences = "Never gonna run around and desert you"; Console.WriteLine("\\n===Final Settings==="); Console.WriteLine("DateTimeFormat: " + PrefG.[DateTimeFormat](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a08c9851a5c9e95249e247964f4d8246c)); Console.WriteLine("Language: " + PrefG.[Language](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#acdb183b72e7c6d518ab2498266d96120)); Console.WriteLine("ZMXFileEncoding: " + PrefG.[ZMXFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a00b869844d613fba6402c2e08433eb7a)); Console.WriteLine("TXTFileEncoding: " + PrefG.[TXTFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a32c4bdb3c87442c8e25f1b3fff721c68)); Console.WriteLine("UseSessionFiles: " + PrefG.[UseSessionFiles](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a05297c825e3d5db4b61b39f312fd0e07)); Console.WriteLine("IncludeCalculatedDataInsession: " + PrefG.[IncludeCalculatedDataInSession](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a5dedeeb661115644cc06de1688cf5c95)); Console.WriteLine("UpdateMostRecentlyUsedList: " + PrefG.[UpdateMostRecentlyUsedList](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a2efa6ee6fe4db0f5cc839ab473462272)); Console.WriteLine("UserPreferences: " + PrefG.[UserPreferences](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#ac46784a53f375871f7050942ea3ef76b)); Console.WriteLine("\\nPress any key to continue..."); Console.ReadKey(); // Clean up FinishStandaloneApplication(TheApplication); } static void FinishStandaloneApplication([IZOSAPI\_Application](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml) TheApplication) { // Note - TheApplication will close automatically when this application exits, so this isn't strictly necessary in most cases if (TheApplication != null) { TheApplication.[CloseApplication](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#ab662a3cc1b97d8632a324b1137fa943b)(); } } static void LogInfo(string message) { // TODO - add custom logging Console.WriteLine(message); } static void HandleError(string errorMessage) { // TODO - add custom error handling throw new Exception(errorMessage); } } } [ZOSAPI.ZOSAPI\_Connection](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml) **Definition:** ZemaxService.cs:198 [ZOSAPI.ZOSAPI\_Connection.PreferencesFile](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml#a18dc1b1ef3fac28798acc2ecdedd3e08) string PreferencesFile For standalone ZOS-API applications, this controls the file that will be used to specify all OpticStu... **Definition:** ZemaxService.cs:1340 [ZOSAPI.ZOSAPI\_Connection.CreateNewApplication](class_z_o_s_a_p_i_1_1_z_o_s_a_p_i___connection.xhtml#aadc54af7d7415a765592acf23d3a08ef) IZOSAPI_Application CreateNewApplication() Attempts to launch a new instance of Optic Studio in 'headless' mode. Note that although the Optic St... **Definition:** ZemaxService.cs:864 [ZOSAPI.IOpticalSystem](interface_z_o_s_a_p_i_1_1_i_optical_system.xhtml) Represent a complete optical system. A IOpticalSystem corresponds to a single .ZMX file.... **Definition:** Interfaces.cs:687 [ZOSAPI.IPreferences](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml) **Definition:** InterfacesPreferences.cs:16 [ZOSAPI.IPreferences.ResetToDefaults](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml#a46785d61c4607d6b571022ac4a47f208) void ResetToDefaults() [ZOSAPI.IPreferences.General](interface_z_o_s_a_p_i_1_1_i_preferences.xhtml#a962ef89db42273aca29102b6fb812d4a) IPreferencesGeneral General **Definition:** InterfacesPreferences.cs:18 [ZOSAPI.IZOSAPI\_Application](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml) This interface contains all information about the current ZOS-API connection, as well as methods for ... **Definition:** Interfaces.cs:261 [ZOSAPI.IZOSAPI\_Application.Preferences](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a2b0d83df3552a7647a57a22a9496f43d) IPreferences Preferences **Definition:** Interfaces.cs:642 [ZOSAPI.IZOSAPI\_Application.IsValidLicenseForAPI](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a5b8d6c216c668d13d6dcb870698c247f) bool IsValidLicenseForAPI Gets a value indicating whether this the API is currently useable. **Definition:** Interfaces.cs:287 [ZOSAPI.IZOSAPI\_Application.Mode](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a8d2a89bafe9778c14f592276e5a5eb19) ZOSAPI_Mode Mode Gets the current connetion mode. Use this to check if Optic Studio is expecting a user operand / anal... **Definition:** Interfaces.cs:306 [ZOSAPI.IZOSAPI\_Application.LicenseStatus](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#a95179eb8038b629caa12397723aacb3a) LicenseStatusType LicenseStatus Gets the license status. Note that this displays the license edition if successful,... **Definition:** Interfaces.cs:280 [ZOSAPI.IZOSAPI\_Application.CloseApplication](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#ab662a3cc1b97d8632a324b1137fa943b) void CloseApplication() Shut down the Optic Studio process. [ZOSAPI.IZOSAPI\_Application.PrimarySystem](interface_z_o_s_a_p_i_1_1_i_z_o_s_a_p_i___application.xhtml#aca8045fe84351622e0ee58814a2a3364) IOpticalSystem PrimarySystem Gets the primary system. When Mode is ZOSAPI_Mode.Server, this will initially be an empty sequential ... **Definition:** Interfaces.cs:328 [ZOSAPI.Preferences.IPreferencesGeneral](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml) Allows configuration of settings from the OpticStudio Preferences -> General tab in OpticStudio.... **Definition:** InterfacesPreferences.cs:89 [ZOSAPI.Preferences.IPreferencesGeneral.ZMXFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a00b869844d613fba6402c2e08433eb7a) EncodingType ZMXFileEncoding **Definition:** InterfacesPreferences.cs:92 [ZOSAPI.Preferences.IPreferencesGeneral.UseSessionFiles](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a05297c825e3d5db4b61b39f312fd0e07) bool UseSessionFiles **Definition:** InterfacesPreferences.cs:94 [ZOSAPI.Preferences.IPreferencesGeneral.DateTimeFormat](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a08c9851a5c9e95249e247964f4d8246c) DateTimeType DateTimeFormat **Definition:** InterfacesPreferences.cs:90 [ZOSAPI.Preferences.IPreferencesGeneral.UpdateMostRecentlyUsedList](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a2efa6ee6fe4db0f5cc839ab473462272) bool UpdateMostRecentlyUsedList This setting can be used to turn updating of the most recently used lens files in File > Open on or o... **Definition:** InterfacesPreferences.cs:100 [ZOSAPI.Preferences.IPreferencesGeneral.TXTFileEncoding](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a32c4bdb3c87442c8e25f1b3fff721c68) EncodingType TXTFileEncoding **Definition:** InterfacesPreferences.cs:93 [ZOSAPI.Preferences.IPreferencesGeneral.IncludeCalculatedDataInSession](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#a5dedeeb661115644cc06de1688cf5c95) bool IncludeCalculatedDataInSession **Definition:** InterfacesPreferences.cs:95 [ZOSAPI.Preferences.IPreferencesGeneral.UserPreferences](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#ac46784a53f375871f7050942ea3ef76b) string UserPreferences This is a single string in which you can store anything you want. It is saved in your Preferences con... **Definition:** InterfacesPreferences.cs:104 [ZOSAPI.Preferences.IPreferencesGeneral.Language](interface_z_o_s_a_p_i_1_1_preferences_1_1_i_preferences_general.xhtml#acdb183b72e7c6d518ab2498266d96120) LanguageType Language **Definition:** InterfacesPreferences.cs:91 [ZOSAPI.Preferences](namespace_z_o_s_a_p_i_1_1_preferences.xhtml) **Definition:** InterfacesPreferences.cs:30 [ZOSAPI](namespace_z_o_s_a_p_i.xhtml) The ZOSAPI namespace contains classes for initially connecting to zemax. See also ZOSAPI_Connection,... **Definition:** IAS_FieldCurvatureAndDistortion.cs:5 [ZOSAPI.ZOSAPI\_Mode](namespace_z_o_s_a_p_i.xhtml#a254f5f6cb4ff37c2245b456b9bb79d2a) ZOSAPI_Mode **Definition:** Interfaces.cs:77