如何选择打印机？？

[Ask100]

请问我现在有两台打印机安装在机器上。
我改如何在程序中实现两台打印机之间的切换。

[WWWWA]

procedure TForm1.Button1Click(Sender: TObject);
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;

begin
//messagebeep(2);
beep();
Printer.PrinterIndex := ComboBox1.ItemIndex;
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));
ComboBox1.Items := Printer.Printers; {populates ComboBox}
ComboBox1.ItemIndex := Printer.PrinterIndex;
end;

procedure TForm1.ComboBox1Change(Sender: TObject);
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;

begin

Printer.PrinterIndex := ComboBox1.ItemIndex;
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;
上述代码为改变默认打印机

[ydhgj]

在表单上添加一个下拉控件，然后在表单的create事件中添加代码：
全部代码如下：
procedure Tyjkcpddb_form.FormCreate(Sender: TObject);
begin
{ 取得打印机名称列表，并显示缺省的打印机名称 }
combobox1.Items.Assign(Printer.Printers);
combobox1.Text := Printer.Printers[Printer.PrinterIndex];
end;

procedure Tyjkcpddb_form.ComboBox1Change(Sender: TObject);
var
IniFile: TIniFile;
TempStr1, TempStr2: String;
WinIniFileName : array[0..MAX_PATH] of char;
S: array[0..64] of char;
begin
with Printer do
begin
//获得所选打印机的索引号
PrinterIndex := combobox1.ItemIndex;
//把其名称存在临时字符串中
TempStr1 := Printers[PrinterIndex];
//删除打印机名中不必要的部分
System.Delete(TempStr1, Pos(' on ', TempStr1), Length(TempStr1));
GetWindowsDirectory(WinIniFileName, sizeof(WinIniFileName));
//获取系统路径
StrCat(WinIniFileName, '\win.ini');
IniFile := TIniFile.Create(WinIniFileName);
//创建INI文件
try
TempStr2 := IniFile.ReadString('Devices', TempStr1, '');
// 获得原先缺省的打印机名称
IniFile.WriteString('windows', 'device', TempStr1 + ',' + TempStr2);
//写入新的默认打印机名称
StrCopy(S, 'windows');
SendMessage(HWND_BROADCAST, WM_WININICHANGE, 0, LongInt(@S));
//通知Windows默认打印机已经改变
finally
IniFile.Free;
end;
end;

最后别忘了在uses中添加：
IniFiles, Printers;