怎样判断用户已经安装好打印机

Question

怎样判断用户已经安装好打印机
如果判断没有安装则给出一个提示

Answer 1

procedure TForm1.ButtonClick(Sender: TObject); 
begin 
  ComboBox1.Clear;
  ComboBox1.Items.Assign(Printer.Printers);
  if ComboBox1.Items.CommaText=''
    then Messagedlg('你需要安装打印机才能打印！',mtError,[mbOk],0);
    else Form1.Print; 
end;  

Answer 2

1 读注册表
2 用EnumPrinters
The EnumPrinters function enumerates available printers, print servers, domains, or print providers. BOOL EnumPrinters(
  DWORD Flags,         // printer object types
  LPTSTR Name,         // name of printer object
  DWORD Level,         // information level
  LPBYTE pPrinterEnum, // printer information buffer
  DWORD cbBuf,         // size of printer information buffer
  LPDWORD pcbNeeded,   // bytes received or required
  LPDWORD pcReturned   // number of printers enumerated
);

Answer 3

Procedure TForm1.Button1Click(Sender:TObject);
var
  appname:array[0..256] of char;
  KeyName:array[0..256] of char;
  DefaultString:array[0..256] of char;
  ReturnedString: array[0..256] of char;
begin
appName:='Windows';
keyname='device';
GetProfileString(appName,KeyName,DefaultString,RetrunedString,Sizeof(ReturnedString));
Edit1.text:=ReturnedString
end;

Answer 4

Procedure TForm1.Button1Click(Sender:TObject);
var
  appname:array[0..256] of char;
  KeyName:array[0..256] of char;
  DefaultString:array[0..256] of char;
  ReturnedString: array[0..256] of char;
begin
appName:='Windows';
keyname:='device';
GetProfileString(appName,KeyName,DefaultString,ReturnedString,Sizeof(ReturnedString));
Edit1.text:=ReturnedString
end;

Answer 5

hansion3406(阿木)的是最简单的也是最好的。