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Whilst VB allows you to determine if the standard, recognised clipboard formats
are on the clipboard, you can't determine if any other formats are present. So,
for example, if you want to know if the clipboard contains data from Excel (which
always pastes at least its own customised format called 'Wk1'), or if you want to
determine whether Rich Text format is available to enable a Paste menu, you can't do it.
This tip shows how to determine all the formats currently available on the clipboard,
including the customised formats.
Start a new project in VB. Add a Command button and a ListBox to the project's form, then add the following
code:
Private Declare Function CountClipboardFormats Lib "USER32" () As Long
Private Declare Function EnumClipboardFormats Lib "USER32" (ByVal wFormat As Long) As Long
Private Declare Function OpenClipboard Lib "USER32" (ByVal hWnd As Long) As Long
Private Declare Function CloseClipboard Lib "USER32" () As Long
Private Declare Function GetClipboardFormatName Lib "USER32" Alias "GetClipboardFormatNameA" (ByVal wFormat As Long, ByVal lpString As String, ByVal nMaxCount As Long) As Long
Private Enum EPredefinedClipboardFormatConstants
[_First] = 1
CF_TEXT = 1
CF_BITMAP = 2
CF_METAFILEPICT = 3
CF_SYLK = 4
CF_DIF = 5
CF_TIFF = 6
CF_OEMTEXT = 7
CF_DIB = 8
CF_PALETTE = 9
CF_PENDATA = 10
CF_RIFF = 11
CF_WAVE = 12
CF_UNICODETEXT = 13
CF_ENHMETAFILE = 14
CF_HDROP = 15
CF_LOCALE = 16
CF_MAX = 17
[_Last] = 17
End Enum
Private Property Get FormatName( _
ByVal lFormatId As Long _
) As String
' Returns the format name for a clipboard format id:
Dim lSize As Long
Dim sBuf As String
Dim lR As Long
If (lFormatId >= EPredefinedClipboardFormatConstants.[_First] And lFormatId <= EPredefinedClipboardFormatConstants.[_Last]) Then
' For pre-defined formats, we have to make the text
' up ourselves:
Select Case lFormatId
Case CF_TEXT
FormatName = "Text"
Case CF_BITMAP
FormatName = "Bitmap Picture"
Case CF_METAFILEPICT
FormatName = "Meta-File Picture"
Case CF_SYLK
FormatName = "Microsoft Symbolic Link (SYLK) data."
Case CF_DIF
FormatName = "Software Arts' Data Interchange information."
Case CF_TIFF = 6
FormatName = "Tagged Image File Format (TIFF) Picture"
Case CF_OEMTEXT
FormatName = "Text (OEM)"
Case CF_DIB
FormatName = "DIB Bitmap Picture"
Case CF_PALETTE
FormatName = "Colour Palette"
Case CF_PENDATA
FormatName = "Pen Data"
Case CF_RIFF
FormatName = "RIFF Audio data"
Case CF_WAVE
FormatName = "Wave File"
Case CF_UNICODETEXT
FormatName = "Text (Unicode)"
Case CF_ENHMETAFILE
FormatName = "Enhanced Meta-File Picture"
Case CF_HDROP
FormatName = "File List"
Case CF_LOCALE
FormatName = "Text Locale Identifier"
End Select
Else
' For custom formats, we can ask the Clipboard for
' the registered name:
lSize = 255
sBuf = String$(lSize, 0)
lR = GetClipboardFormatName(lFormatId, sBuf, lSize)
If (lR <> 0) Then
FormatName = Left$(sBuf, lR)
End If
End If
End Property
Private Sub Command1_Click()
Dim lR As Long
Dim iCount As Long
List1.Clear
If (OpenClipboard(Me.hWnd)) Then
lR = EnumClipboardFormats(0)
If (lR <> 0) Then
Do
iCount = iCount + 1
List1.AddItem FormatName(lR)
List1.ItemData(List1.NewIndex) = lR
lR = EnumClipboardFormats(lR)
Loop While lR <> 0
End If
End If
CloseClipboard
End Sub
When you click the command button, the list box will be filled with a list of
available data formats. The List field is set to the format name, and the item
data of each item is set to the clipboard format's ID. To see custom formats in
the list, try copying something from Word, Write or Internet Explorer before clicking
the button.
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