StartProjectMode Enumeration
Specifies the start mode for the ArcGIS Pro application
Set GeneralOptions to Use Defaults
//Default options can be set regardless of the value of the "companion"
//path (to a project, folder, gdb, toolbox, etc.). The path value is ignored if
//the option setting does not use it. This is the same behavior as on the Pro UI.
ApplicationOptions.GeneralOptions.StartupOption = StartProjectMode.ShowStartPage;
ApplicationOptions.GeneralOptions.HomeFolderOption = OptionSetting.UseDefault;
ApplicationOptions.GeneralOptions.DefaultGeodatabaseOption = OptionSetting.UseDefault;
ApplicationOptions.GeneralOptions.DefaultToolboxOption = OptionSetting.UseDefault;//set default option first
//path values can (optionally) be set (back) to null if their
//"companion" option setting is the default option.
if (ApplicationOptions.GeneralOptions.StartupOption != StartProjectMode.WithDefaultProject)
ApplicationOptions.GeneralOptions.StartupProjectPath = null;
if (ApplicationOptions.GeneralOptions.HomeFolderOption == OptionSetting.UseDefault)
ApplicationOptions.GeneralOptions.CustomHomeFolder = null;
if (ApplicationOptions.GeneralOptions.DefaultGeodatabaseOption == OptionSetting.UseDefault)
ApplicationOptions.GeneralOptions.CustomDefaultGeodatabase = null;
if (ApplicationOptions.GeneralOptions.DefaultToolboxOption == OptionSetting.UseDefault)
ApplicationOptions.GeneralOptions.CustomDefaultToolbox = null;
Target Platforms: Windows 11, Windows 10
ArcGIS Pro version: 3 or higher.