کلاسهای VB

[بابک زواری]

یک کلاس توی VB تعریف کردم با یک سری تابع و خرت و پرت دیگه
ولی وقتی یک object رو از این نوع تعریف میکنم بعد میخوام به این
توابع و propertiesها دسترسی پیدا کنم با گذاشتن نقطه لیست
اونا نمایش داده نمیشه ؟ علت از چی میتونه باشه ؟

[kochol]

سلام
ببین این بدردت میخوره

Option Explicit

'This is the BitmapBuffer Class. It basically handles the creation
'and maintenance of Memory Device Contexts used to store graphic
'images in memory. You can use the BitmapBuffer for background images,
'sprite animations, scrolling backgrounds, and off-screen painting
'areas. The BitmapBuffer object has four properties & two methods:
'
' BitmapFile Indicates the path & filename of the bitmap that
' will be loaded into this BitmapBuffer. The BitmapBuffer
' also uses the dimensions of the bitmap to determine
' the size of the buffer. <PROPERTY> <READ/WRITE>
'
' Handle Returns the handle to the device context (hDC) of
' this BitmapBuffer. <PROPERTY> <READ-ONLY>
'
' Height Returns the Height of this BitmapBuffer
' <Property> <READ-ONLY>
'
' Width Returns the Width of this BitmapBuffer
' <Property> <READ-ONLY>
'
' Create Creates the memory device context for this BitmapBuffer
' and, optionally, loads the bitmap set by the
' BitmapFile property. If no BitmapFile is set,
' you need to specify the width and height of the
' BitmapBuffer when you use Create. <METHOD>
'
' USAGE: object.Create [Width] [,Height]
'
' Destroy Frees the resources used by this BitmapBuffer.
' Any BitmapBuffers you create are destroyed automatically
' if they are no longer referenced by your program.
' If you want to explicitly destroy it, use this method.
'
' USAGE: object.Destroy

'Variables used internally by the BitmapBuffer Class
Private BufferhDC As Long 'Internal handle to the memory DC.
' Used to return the Handle property.
Private OldObj As Long 'Used to store the old object (Windows stock bitmap)
' when BitmapFile is selected into the DC
Private BufferBM As String 'Internal path & filename of the bitmap
' Used to return the BitmapFile property.
Private BMWidth As Long 'Used to store the width of the Bitmap
' and return the Width property
Private BMHeight As Long 'Used to store the Height of the Bitmap
' and return the Height property

Property Let BitmapFile(ByVal NewBMFile As String)
'When the BitmapFile property is set, this procedure is called.
'It reads the header information of the bitmap to determine the
'width and height of the bitmap. It then sets the width and
'height of the buffer to match.

Dim BMFileNum As Integer 'File handle for the bitmap

BufferBM = NewBMFile
BMFileNum = FreeFile 'Gets the next free file handle

End Property

Property Get BitmapFile() As String
'When the BitmapFile property is read, this procedure is invoked.
'Return the path & name of the bitmap file.
BitmapFile = BufferBM
End Property

Sub Create(Optional BufWidth As Variant, Optional BufHeight As Variant)
'When the Create method is invoked, this procedure is called
'Check to see if BitmapFile is not set
If BufferBM = "" Then
'If it isn't, first check if the parameters BufWidth & BufHeight exist
If IsMissing(BufWidth) Or IsMissing(BufHeight) Then Exit Sub
'and if they do, are they greater than zero.
If (BufWidth <= 0) And (BufHeight <= 0) Then
'If they aren't, set the height & width to 0 and exit the procedure.
BMWidth = 0
BMHeight = 0
Exit Sub
Else
'If they are, then set the width & height of the buffer
BMWidth = BufWidth
BMHeight = BufHeight
End If
End If
'Create a memory device context (buffer)
BufferhDC = NewDC(Screen.ActiveForm.hDC, BMWidth, BMHeight)
'If BitmapFile is set, load the bitmap into the buffer
If BufferBM <> "" Then OldObj = SelectObject(BufferhDC, LoadPicture(BufferBM))
End Sub

Sub Destroy()
'When the Destroy method is invoked, this procedure is called
'Create a temporary variable to store the results
'of the SelectObject function.
Dim tmpObj As Long

'Select the original object (Windows stock bitmap) back into the
'memory DC. This basically restores things the way they were before
'we created this BitmapBuffer.
tmpObj = SelectObject(BufferhDC, OldObj)

'Delete the memory DC and free the resources we used.
DeleteDC BufferhDC
End Sub

Property Get Handle() As Long
'When the Handle property is read, this procedure is invoked.
'Return the Handle of the BitmapBuffer.
Handle = BufferhDC
End Property


Property Get Height()
'When the Height property is read, this procedure is invoked.
'Return the height of the BitmapBuffer.
Height = BMHeight
End Property

Property Get Width()
'When the Width property is read, this procedure is invoked.
'Return the width of the BitmapBuffer.
Width = BMWidth
End Property

Private Sub Class_Terminate()
'This procedure is invoked when no more instances of the
'BitmapBuffer class are referenced, such as when you
'end the program. This procedure is the same as the Destroy method.
'Create a temporary variable to store the results
'of the SelectObject function.
Dim tmpObj As Long

'Select the original object (Windows stock bitmap) back into the
'memory DC. This basically restores things the way they were before
'we created this BitmapBuffer.
If OldObj > 0 Then tmpObj = SelectObject(BufferhDC, OldObj)

'Delete the memory DC and free the resources we used.
If BufferhDC > 0 Then DeleteDC BufferhDC
End Sub

[بابک زواری]

علتش این بود که اگر یک api رو وسط کلاس declare کنی این مشکل پیش میاد
باید تمام این declare ها در ابتدا صورت بگیره