Mega Code Archive
Printerdefault
<![CDATA[
Hi,
Here's some code from a component I wrote.... FPrintDevice is the
printer from the available printers retrieved using
GetProfileString......not the printer.printers. I'll send the component
directly to you... so you can get the full thing.
The component uses the printer.printers to get the device, port and
printer name from the getprofilestring (ini in Win95, registry in NT),
then uses that information to set the default. I also made a
showprinter procedure to lauch the printers window so you can
verify that that printer did indeed change.
procedure TbmPrinterInfo.Execute;
var
prnTemp: string;
BufferVar: Pchar;
BufSize, ReturnCode: integer;
const
cs1: pchar = 'Windows';
begin
if Trim(FPrintDevice)<>'' then
begin
BufSize := 254;
GetMem(BufferVar, BufSize);
try
ReturnCode := GetProfileString('Devices', pchar(FPrintDevice), #0, BufferVar, BufSize);
if (ReturnCode > 0) and (trim(strpas(BufferVar)) <> '') then
begin
prnTemp := FPrintDevice + ',' + strpas(BufferVar);
while GetProfileString('Device', 'Device', #0, BufferVar, BufSize) > 0 do
WriteProfileString('Windows', 'Device', #0);
WriteProfileString('Windows', 'Device', pchar(prnTemp));
case Win32Platform of
VER_PLATFORM_WIN32_NT:
SendMessage(HWND_BROADCAST, WM_WININICHANGE, 0, LongInt(cs1));
VER_PLATFORM_WIN32_WINDOWS:
SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, LongInt(cs1));
end; { case }
end;
finally
FreeMem(BufferVar);
end;
end else
begin
if csDesigning in ComponentState then
ShowMessage('Select a printer before setting default.');
end;
end;
__________________________________________________________________________
bmclean@MNSi.net
To me, there's no better symbol for the world than a grasshopper lying
dead on a gravel road, and maybe there's a globe lying next to him.
Deep Thoughts by Jack Handey
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*******************************************************************
Article explaining why using WriteProfileString( 'windows', 'device', Device );
works in NT...
The traditional approach to setting the default printer, and one that should
work according to documentation, is to enumerate the Printers collection
until the desired printer is located, then assigning that to the Printer
object. This doesn't work as advertised. The printer name will change, but
output still goes to the original default device.
Under Win9x, installed printers are listed in win.ini under the PrinterPorts
key, with the system default printer listed under the Device key, and various
documentation suggests that changing this key sets the default printer. But if
you examine the win.ini file on a WinNT/2000 system, the file does not contain
any printer port or default printer info. Not to worry.
By default, using either GetProfileString / WriteProfileString or
GetPrivateProfileString / WritePrivateProfileString on WinNT/2000, the APIs
actually first look to the registry under the key
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping
for the ini file name of interest. If its not found, then the physical disk ini
file itself is checked.
In the case of win.ini, if its found in the registry under the key above, it is
further examined for the section name desired (PrinterPorts). The registry
value assigned to this key point to the location within the registry of the
actual installed printers data (which in my case this points to
"USR:Software\Microsoft\Windows NT\CurrentVersion\PrinterPorts").
Under the PrinterPorts key the installed printers are listed. As well, the
default printer setting corresponding to the expected ini file "Device" entry
is stored in the \windows section under that same parent key. When an operation
has been mapped, the Get(Private)ProfileString functions retrieve information
from the registry, not from the physical initialization file. This change in
the storage location has no effect on the function's behavior and is transparent
to the calling application.
What this all means is simply that there is no need to resort to registry
reading/writing calls - the familiar ini file APIs can be utilized to change
the default printer....
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