Title: How to change the default Windows printer from Delphi code
Here's how to change the default Windows printer if you know the printer's name:
~~~~~~~~~~~~~~~~~~~~~~~~~
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
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Note: Using Delphi's global Printer variable (of type TPrinter) you can fill a ComboBox with all available printers:
cboPrinters.Items.Assign(Printer.Printers) ;
Then, when a user clicks some button (for example) call the ChangeDefaultPrinter procedure:
if cboPrinters.ItemIndex = -1 then Exit;
ChangeDefaultPrinter(cboPrinters.Items[cboPrinters.ItemIndex]) ;