如何测试打印机(200分)

请问如何写程序测出打印机以下几种状态：
1。未打开电源或无法连接
2。打印机没纸
3。打印完毕
急用，谢谢各位！
jonyhuang

API 的 GetPrinter；
我在msdn的知识库找到了答案。
请查阅msdn ：Q160129
HOWTO: Get the Status of a Printer and a Print Job

下面是其中的代码，得到打印机状态和打印作业的：
BOOL GetJobs(HANDLE hPrinter, /* handle to the printer */
JOB_INFO_2 **ppJobInfo, /* pointer to be filled */
int *pcJobs, /* count of jobs filled */
DWORD *pStatus) /* print Queue status */
{
DWORD cByteNeeded,
nReturned,
cByteUsed;
JOB_INFO_2 *pJobStorage = NULL;
PRINTER_INFO_2 *pPrinterInfo = NULL;

/* Get the buffer size needed */
if (!GetPrinter(hPrinter, 2, NULL, 0, &cByteNeeded))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
return FALSE;
}

pPrinterInfo = (PRINTER_INFO_2 *)malloc(cByteNeeded);
if (!(pPrinterInfo))
/* failure to allocate memory */
return FALSE;

/* get the printer info */
if (!GetPrinter(hPrinter,
2,
(LPSTR)pPrinterInfo,
cByteNeeded,
&cByteUsed))
{
/* failure to access the printer */
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}

/* Get job storage space */
if (!EnumJobs(hPrinter,
0,
pPrinterInfo->cJobs,
2,
NULL,
0,
(LPDWORD)&cByteNeeded,
(LPDWORD)&nReturned))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}
}

pJobStorage = (JOB_INFO_2 *)malloc(cByteNeeded);
if (!pJobStorage)
{
/* failure to allocate Job storage space */
free(pPrinterInfo);
pPrinterInfo = NULL;
return FALSE;
}

ZeroMemory(pJobStorage, cByteNeeded);

/* get the list of jobs */
if (!EnumJobs(hPrinter,
0,
pPrinterInfo->cJobs,
2,
(LPBYTE)pJobStorage,
cByteNeeded,
(LPDWORD)&cByteUsed,
(LPDWORD)&nReturned))
{
free(pPrinterInfo);
free(pJobStorage);
pJobStorage = NULL;
pPrinterInfo = NULL;
return FALSE;
}

/*
* Return the information
*/
*pcJobs = pPrinterInfo->cJobs;
*pStatus = pPrinterInfo->Status;
*ppJobInfo = pJobStorage;
free(pPrinterInfo);

return TRUE;
}

BOOL IsPrinterError(HANDLE hPrinter)
{
JOB_INFO_2 *pJobs;
int cJobs,
i;
DWORD dwPrinterStatus;

/*
* Get the state information for the Printer Queue and
* the jobs in the Printer Queue.
*/
if (!GetJobs(hPrinter, &pJobs, &cJobs, &dwPrinterStatus))
return FALSE;

/*
* if the Printer reports an error, believe it
*/
if (dwPrinterStatus &
(PRINTER_STATUS_ERROR |
PRINTER_STATUS_PAPER_JAM |
PRINTER_STATUS_PAPER_OUT |
PRINTER_STATUS_PAPER_PROBLEM |
PRINTER_STATUS_OUTPUT_BIN_FULL |
PRINTER_STATUS_NOT_AVAILABLE |
PRINTER_STATUS_NO_TONER |
PRINTER_STATUS_OUT_OF_MEMORY |
PRINTER_STATUS_OFFLINE |
PRINTER_STATUS_DOOR_OPEN))
{
return TRUE;
}

/*
* Find the Job in the Queue that is printing
*/
for (i=0;
i < cJobs;
i++)
{
if (pJobs.Status &amp;
JOB_STATUS_PRINTING)
{
/*
* If the job is in an error state,
* report an error for the printer.
* Code could be inserted here to
* attempt an interpretation of the
* pStatus member as well.
*/
if (pJobs.Status &amp;
(JOB_STATUS_ERROR |
JOB_STATUS_OFFLINE |
JOB_STATUS_PAPEROUT |
JOB_STATUS_BLOCKED_DEVQ))
{
return TRUE;
}
}
}

/*
* No error condition
*/
return FALSE;

}

其实也可以这样（一个例子的方法）
建一个不可见的COMBOBOX
begin

combobox.clear;
combobox.items.assign(printer.printers);
if combobox.items.commatext='' then
{报错}
else
{继续}
。
。
end;

至于其他怎么样，我也不知道了。
关注~~~~~~~~~~

多人接受答案了。