__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
        //打印机列表
        TPrinter *printer = new TPrinter();
        Cb_Prints->Items = printer->Printers;
        Cb_Prints->ItemIndex = 0;
        delete  printer;

}
//—————————————————————————

void __fastcall TForm1::Button1Click(TObject *Sender)
{
                        if(PausePrinter(Cb_Prints->Text  ))
                                lb_PrintState->Caption = "打印机暂停";

}
//—————————————————————————

bool TForm1::PausePrinter(String PrinterName)
{
        bool flag = false;
        HANDLE p = NULL;
        if(OpenPrinter(PrinterName.c_str(),&p,NULL))
        {
              flag = SetPrinter(p,0,NULL,PRINTER_CONTROL_PAUSE);
        }
        ClosePrinter(p);

        return flag;
}

bool TForm1::ResumePrinter(String PrinterName)
{
        bool flag = false;
        HANDLE p = NULL;
        if(OpenPrinter(PrinterName.c_str(),&p,NULL))
        {
                flag = SetPrinter(p,0,NULL,PRINTER_CONTROL_RESUME);
        }
        ClosePrinter(p);

        return flag;
}

void __fastcall TForm1::Button2Click(TObject *Sender)
{
        if(ResumePrinter(Cb_Prints->Text ))
                                lb_PrintState->Caption = "打印机正常";
}

怎么总是不成功

谢谢.