获取默认打印机名：
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; 更改默认打印机：需要Uses WinSpool
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; //ChangeDefaultPrinter
ChangeDefaultPrinter函数 在D7下使用SetDefaultPrinterA，在Delphi2010以上版本使用SetDefaultPrinterW
procedure TDM.ChangeDefaultPrinter(const Name: string);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;//这个函数也可以更改打印机，效果没有上面的好