Option Explicit
Private Type PALETTEENTRY
peRed As Byte
peGreen As Byte
peBlue As Byte
peFlags As Byte
End Type
Private Type LOGPALETTE
palVersion As Integer
palNumEntries As Integer
palPalEntry(255) As PALETTEENTRY
End Type
Private Type GUID
Data1 As Long
Data2 As Integer
Data3 As Integer
Data4(7) As Byte
End Type
Private Const RASTERCAPS As Long = 38
Private Const RC_PALETTE As Long = &H100
Private Const SIZEPALETTE As Long = 104
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Declare Function CreateCompatibleDC Lib "GDI32" (ByVal hDC As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "GDI32" (ByVal hDC As Long, _
ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function GetDeviceCaps Lib "GDI32" (ByVal hDC As Long, ByVal _
iCapabilitiy As Long) As Long
Private Declare Function GetSystemPaletteEntries Lib "GDI32" (ByVal hDC As Long, _
ByVal wStartIndex As Long, ByVal wNumEntries As Long, lpPaletteEntries _
As PALETTEENTRY) As Long
Private Declare Function CreatePalette Lib "GDI32" (lpLogPalette As LOGPALETTE) _
As Long
Private Declare Function SelectObject Lib "GDI32" (ByVal hDC As Long, ByVal hObject _
As Long) As Long
Private Declare Function BitBlt Lib "GDI32" (ByVal hDCDest As Long, ByVal XDest As _
Long, ByVal YDest As Long, ByVal nWidth As Long, ByVal nHeight As Long, _
ByVal hDCSrc As Long, ByVal XSrc As Long, ByVal YSrc As Long, ByVal dwRop _
As Long) As Long
Private Declare Function DeleteDC Lib "GDI32" (ByVal hDC As Long) As Long
Private Declare Function GetForegroundWindow Lib "user32" () As Long
Private Declare Function SelectPalette Lib "GDI32" (ByVal hDC As Long, ByVal hPalette _
As Long, ByVal bForceBackground As Long) As Long
Private Declare Function RealizePalette Lib "GDI32" (ByVal hDC As Long) As Long
Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long, lpRect As _
RECT) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hDC As _
Long) As Long
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Type PicBmp
Size As Long
Type As Long
hBmp As Long
hPal As Long
Reserved As Long
End Type
Private Declare Function OleCreatePictureIndirect Lib "olepro32.dll" (PicDesc As _
PicBmp, RefIID As GUID, ByVal fPictureOwnsHandle As Long, IPic As IPicture) As Long
Private Declare Function GetComputerName Lib "kernel32" Alias "GetComputerNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Dim ComputerName As String '本機名稱，用來區分不同的機器所生成的圖像。
'創建BMP位圖
Public Function CreateBitmapPicture(ByVal hBmp As Long, ByVal hPal As Long) As Picture
Dim r As Long
Dim Pic As PicBmp
Dim IPic As IPicture
Dim IID_IDispatch As GUID
'填充IDispatch界面
With IID_IDispatch
.Data1 = &H20400
.Data4(0) = &HC0
.Data4(7) = &H46
End With
'填充Pic
With Pic
.Size = Len(Pic) '註釋： Pic結構長度
.Type = vbPicTypeBitmap '註釋： 圖象類型
.hBmp = hBmp '註釋： 位圖句柄
.hPal = hPal '註釋： 調色板句柄
End With
'建立Picture圖象
r = OleCreatePictureIndirect(Pic, IID_IDispatch, 1, IPic)
'返回Picture對象
Set CreateBitmapPicture = IPic
End Function
'截圖處理
Public Function CaptureWindow(ByVal hWndSrc As Long, ByVal Client As Boolean, ByVal _
LeftSrc As Long, ByVal TopSrc As Long, ByVal WidthSrc As Long, ByVal HeightSrc _
As Long) As Picture
Dim hDCMemory As Long '保存截取圖象的目標設備
Dim hBmp As Long
Dim hBmpPrev As Long
Dim r As Long
Dim hDCSrc As Long '要截取圖象的源設備
Dim hPal As Long
Dim hPalPrev As Long
Dim RasterCapsScrn As Long
Dim HasPaletteScrn As Long
Dim PaletteSizeScrn As Long
Dim LogPal As LOGPALETTE
'GetDC傳回用於寫入窗口顯示區域的設備內容句柄,而GetWindowDC傳回寫入整個窗口的設備內容句柄
'區別在於GetDC不包括邊框、滾動條、標題欄、菜單等，而GetWindowDC則包括
If Client Then '如果為真，即指定是客戶區（不包括標題欄等）
hDCSrc = GetDC(hWndSrc) 'GetDC檢索壹指定窗口的客戶區域或整個屏幕的顯示設備上下文的句柄
Else '否則用GetWindowDC尋找後獲取
hDCSrc = GetWindowDC(hWndSrc)
End If
hDCMemory = CreateCompatibleDC(hDCSrc) '創建壹塊與hDCSrc設備場景壹樣的內存區
hBmp = CreateCompatibleBitmap(hDCSrc, WidthSrc, HeightSrc) '創建壹幅與設備有關位圖
hBmpPrev = SelectObject(hDCMemory, hBmp) 'SelectObject將位圖放入設備場景中
'獲得屏幕屬性
RasterCapsScrn = GetDeviceCaps(hDCSrc, RASTERCAPS) '根據指定設備場景代表的設備的功能返回信息
HasPaletteScrn = RasterCapsScrn And RC_PALETTE
PaletteSizeScrn = GetDeviceCaps(hDCSrc, SIZEPALETTE)
'如果屏幕對象有調色板則獲得屏幕調色板
If HasPaletteScrn And (PaletteSizeScrn = 256) Then
'建立屏幕調色板的拷貝
LogPal.palVersion = &H300
LogPal.palNumEntries = 256
r = GetSystemPaletteEntries(hDCSrc, 0, 256, LogPal.palPalEntry(0)) '獲取系統調色板
hPal = CreatePalette(LogPal) 'CreatePalette調色板函數
'將新建立的調色板選入建立的內存繪圖句柄中
hPalPrev = SelectPalette(hDCMemory, hPal, 0)
r = RealizePalette(hDCMemory) 'RealizePalette函數使系統恢復當前選中的邏輯調色板中的值
End If
'拷貝圖象
r = BitBlt(hDCMemory, 0, 0, WidthSrc, HeightSrc, hDCSrc, LeftSrc, TopSrc, vbSrcCopy)
hBmp = SelectObject(hDCMemory, hBmpPrev)
If HasPaletteScrn And (PaletteSizeScrn = 256) Then
hPal = SelectPalette(hDCMemory, hPalPrev, 0)
End If
'釋放資源
r = DeleteDC(hDCMemory)
r = ReleaseDC(hWndSrc, hDCSrc)
Set CaptureWindow = CreateBitmapPicture(hBmp, hPal)
End Function
Private Sub Form_Load()
Dim sBuffer As String
Dim lSize As Long
sBuffer = Space$(255)
lSize = Len(sBuffer)
Call GetComputerName(sBuffer, lSize)
ComputerName = Trim(Left$(sBuffer, lSize))
End Sub
Private Sub Timer1_Timer()
Dim hWndScreen As Long, CaptureScreen As StdPicture
'獲得桌面的窗口句柄
hWndScreen = GetDesktopWindow()
Set CaptureScreen = CaptureWindow(hWndScreen, False, 0, 0, Screen.Width _
\ Screen.TwipsPerPixelX, Screen.Height \ Screen.TwipsPerPixelY)
SavePicture CaptureScreen, "\\WWW-94E37D893B8\D$\ClientScreen\image" & ComputerName & ".bmp"
Call iniPara
End Sub
'當發現有異常情況時，往往需要縮短采樣間隔，下面iniPara函數可實現改變定時器的Interval屬性的功能。
Private Function iniPara() '讀取服務器上的Client.ini文件，初使化定時器的間隔。
Dim sBuffer As String
Dim lSize As Long
Dim TimerInterval As Integer '采樣間隔
Open "\\WWW-94E37D893B8\D$\ClientScreen\Client.ini" For Input As #1
Line Input #1, sBuffer
lSize = InStr(1, sBuffer, "=")
Timer1.Interval = Val(Mid(sBuffer, lSize + 1))
Close (1)
End Function