如何检测打印机状态

[hblmh]

如何检测打印机状态，如联机、缺纸、缺墨等

[TechnoFantasy]

In a module:


Option Explicit

Public Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA" _
(ByVal pPrinterName As String, _
phPrinter As Long, _
pDefault As PRINTER_DEFAULTS) _
As Long

Public Declare Function GetPrinter Lib "winspool.drv" Alias "GetPrinterA" _
(ByVal hPrinter As Long, _
ByVal Level As Long, _
pPrinter As Byte, _
ByVal cbBuf As Long, _
pcbNeeded As Long) _
As Long

Public Declare Function ClosePrinter Lib "winspool.drv" _
(ByVal hPrinter As Long) _
As Long

Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(Destination As Any, _
Source As Any, _
ByVal Length As Long)

' constants for PRINTER_DEFAULTS structure
Public Const STANDARD_RIGHTS_REQUIRED = &HF0000
Public Const PRINTER_ACCESS_ADMINISTER = &H4
Public Const PRINTER_ACCESS_USE = &H8
Public Const PRINTER_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED Or _
PRINTER_ACCESS_ADMINISTER Or PRINTER_ACCESS_USE)

' constants for DEVMODE structure
Public Const CCHDEVICENAME = 32
Public Const CCHFORMNAME = 32

Public Type PRINTER_DEFAULTS
pDatatype As String
pDevMode As Long
DesiredAccess As Long
End Type

Type PRINTER_INFO_2
pServerName As Long
pPrinterName As Long
pShareName As Long
pPortName As Long
pDriverName As Long
pComment As Long
pLocation As Long
pDevMode As Long
pSepFile As Long
pPrintProcessor As Long
pDatatype As Long
pParameters As Long
pSecurityDescriptor As Long
Attributes As Long
Priority As Long
DefaultPriority As Long
StartTime As Long
UntilTime As Long
Status As Long
cJobs As Long
AveragePPM As Long
End Type

Public Const ERROR_INSUFFICIENT_BUFFER = 122
Public Const PRINTER_STATUS_BUSY = &H200
Public Const PRINTER_STATUS_DOOR_OPEN = &H400000
Public Const PRINTER_STATUS_ERROR = &H2
Public Const PRINTER_STATUS_INITIALIZING = &H8000
Public Const PRINTER_STATUS_IO_ACTIVE = &H100
Public Const PRINTER_STATUS_MANUAL_FEED = &H20
Public Const PRINTER_STATUS_NO_TONER = &H40000
Public Const PRINTER_STATUS_NOT_AVAILABLE = &H1000
Public Const PRINTER_STATUS_OFFLINE = &H80
Public Const PRINTER_STATUS_OUT_OF_MEMORY = &H200000
Public Const PRINTER_STATUS_OUTPUT_BIN_FULL = &H800
Public Const PRINTER_STATUS_PAGE_PUNT = &H80000
Public Const PRINTER_STATUS_PAPER_JAM = &H8
Public Const PRINTER_STATUS_PAPER_OUT = &H10
Public Const PRINTER_STATUS_PAPER_PROBLEM = &H40
Public Const PRINTER_STATUS_PAUSED = &H1
Public Const PRINTER_STATUS_PENDING_DELETION = &H4
Public Const PRINTER_STATUS_PRINTING = &H400
Public Const PRINTER_STATUS_PROCESSING = &H4000
Public Const PRINTER_STATUS_TONER_LOW = &H20000
Public Const PRINTER_STATUS_USER_INTERVENTION = &H100000
Public Const PRINTER_STATUS_WAITING = &H2000
Public Const PRINTER_STATUS_WARMING_UP = &H10000


Function CheckPrinterStatus(PrinterName As String) As String

Dim hPrinter As Long
Dim ByteBuf As Long, BytesNeeded As Long
Dim PI2 As PRINTER_INFO_2

Dim PrinterInfo() As Byte

Dim result As Long, LastError As Long
Dim PrinterName As String, tempStr As String
Dim NumJI2 As Long
Dim pDefaults As PRINTER_DEFAULTS

CheckPrinterStatus = ""

pDefaults.DesiredAccess = PRINTER_ALL_ACCESS

'Call API to get a handle to the printer
result = OpenPrinter(PrinterName, hPrinter, pDefaults)
If result = 0 Then
'If an error occured, display an error and exit sub
MsgBox "Cannot open printer " & PrinterName & ", Error: " _
& Err.LastDllError
Exit Function
End If

'Init BytesNeeded
BytesNeeded = 0

'Clear the error object of any errors
Err.Clear

'Determine the buffer size needed to get printer info
result = GetPrinter(hPrinter, 2, 0&, 0&, BytesNeeded)

'Check for error calling GetPrinter
If Err.LastDllError <> ERROR_INSUFFICIENT_BUFFER Then
ClosePrinter hPrinter
Exit Function
End If

'Due to a problem with GetPrinter, we must allocate a buffer as
'much as 3 times larger than the value returned by the initial
'call to GetPrinter.
ReDim PrinterInfo(1 To BytesNeeded * 3)

ByteBuf = BytesNeeded

'Call GetPrinter to get the status
result = GetPrinter(hPrinter, 2, PrinterInfo(1), ByteBuf, _
BytesNeeded * 3)

'Check for errors
If result = 0 Then
'Determine the error that occured
LastError = Err.LastDllError()
ClosePrinter hPrinter
Exit Function
End If

'Copy contents of printer status byte array into a
'PRINTER_INFO_2 structure to separate the individual elements
CopyMemory PI2, PrinterInfo(1), Len(PI2)

'Check if printer is in ready state
If PI2.Status = 0 Then
CheckPrinterStatus = "Ready"
Else
CheckPrinterStatus = PI2.Status
End If

'Close the printer handle
ClosePrinter hPrinter
End Function

[TechnoFantasy]

微软KB中的文章：

http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B202480

[TechnoFantasy]

Getting the status of the selected printer from Visual Basic:

http://www.merrioncomputing.com/Programming/PrintStatus.htm

[hblmh]

装没装打印机运行结果都是“Cannot open printer ”我用的打印机是Canon BJC4650
即：OpenPrinter(PrinterName, hPrinter, pDefaults)值始终为0。