Delphi sets the system default printer

Get the default printer name:

Function TForm1.GetDefaultPrinterName: string;var iSize: Integer; sIniFile, sSection, sKeyName: PChar;begin iSize: = 256; sIniFile: = 'win.ini'; sSection: =' windows'; sKeyName: = 'device'; SetLength (Result, iSize); GetPrivateProfileString (sSection, sKeyName, nil, PChar (Result), iSize, sIniFile); Result: = Copy (Result, 0, Pos (',', Result)-1); end

Change the default printer: Uses WinSpool required

Procedure ChangeDefaultPrinter (const Name: string); var W2KSDP: function (pszPrinter: PChar): Boolean; stdcall; H: THandle; Size, Dummy: Cardinal; PI: PPrinterInfo2;begin if (Win32Platform = VER_PLATFORM_WIN32_NT) and (Win32MajorVersion > = 5) then begin @ W2KSDP: = GetProcAddress (GetModuleHandle (winspl), 'SetDefaultPrinterA'); if @ W2KSDP = nil then RaiseLastOSError; if not W2KSDP (PChar (Name)) then RaiseLastOSError; end else begin if not OpenPrinter (PChar (Name), H, nil) then RaiseLastOSError Try GetPrinter (H, 2, nil, 0, @ Size); if GetLastError ERROR_INSUFFICIENT_BUFFER then RaiseLastOSError; GetMem (PI, Size); try if not GetPrinter (H, 2, PI, Size, @ Dummy) then RaiseLastOSError; Pi ^ .Attributes: = Pi ^ .Attributes or PRINTER_ATTRIBUTE_DEFAULT; if not SetPrinter (H, 2, PI, PRINTER_CONTROL_SET_STATUS) then RaiseLastOSError; finally FreeMem (PI); end Finally ClosePrinter (H); end;end; end; / / ChangeDefaultPrinterChangeDefaultPrinter function uses SetDefaultPrinterA under D7 and SetDefaultPrinterWprocedure TDM.ChangeDefaultPrinter (const Name: string) above Delphi2010; var Device: array [0.255] of Char; Driver: array [0.255] of char; Port: array [0.255] of char; s: array [0.255] of Char; hDeviceMode: THandle; I: Integer Begin for I: = 0 to Printer.Printers.Count-1 do if Printer.Printers.Strings [I] = name then begin Printer.PrinterIndex: = I; Break; end; Printer.GetPrinter (Device, Driver, Port, hDeviceMode); StrCopy (s, Device); StrCat (s,','); StrCat (s, Driver); StrCat (s,','); StrCat (s, Port); WriteProfileString ('windows',' device', 's) StrCopy (s, 'windows'); SendMessage (HWND_BROADCAST, WM_WININICHANGE, 0, LongInt (@ s)); end;// this function can also change the printer, the effect is not as good as above