By default LEADTOOLS Virtual Printers are unlocked and any application can print directly to it. The ability to lock a printer must be implemented during installation. Do so by filling the pszPassword member of the PRNPRINTERINFO structure with the password to be used. Lock the printer to prevent other applications from printing directly to it by calling the L_PrnLockPrinter function.
Note: Only printers that were originally created with a password can be locked.
If the printer is locked, when a user tries to print directly to the printer a message box displays saying that printer is locked.
To unlock a printer, call the L_PrnUnlockPrinter function.
To determine whether applications were prevented from directly printing to the specified LEADTOOLS Virtual Printer, call the L_PrnIsPrinterLocked function.