apiownerdrawitem.cls

几个不错的VB例子

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "ApiOwnerDrawItem"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Option Explicit


Public Enum OwnerDrawItemTypes
    ODT_BUTTON = 4
    ODT_COMBOBOX = 3
    ODT_LISTBOX = 2
    ODT_MENU = 1
End Enum

Public Enum OwnerDrawItemActions
    ODA_SELECT = &H2
    ODA_FOCUS = &H4
    ODA_DRAWENTIRE = &H1
End Enum

Public Enum OwnerDrawItemStates
    ODS_CHECKED = &H8
    ODS_DISABLED = &H4
    ODS_FOCUS = &H10
    ODS_GRAYED = &H2
    ODS_SELECTED = &H1
    '\\ Win NT4 +
    ODS_DEFAULT = &H20
    ODS_COMBOBOXEDIT = &H1000
    '\\ Win2k +
    ODS_HOTLIGHT = &H40
    ODS_INACTIVE = &H80
End Enum

Private Type RECT
    Left As Long
    Top As Long
    Right As Long
    Bottom As Long
End Type

Private Type DRAWITEMSTRUCT
    CtlType As Long
    CtlID As Long
    ItemId As Long
    itemAction As Long
    ItemState As Long
    hwndItem As Long
    hdc As Long
    rcItem As RECT
    itemData As Long
End Type

'\\ Private memory handling functions
Private Declare Sub CopyMemoryDRAWITEMSTRUCT Lib "kernel32" Alias "RtlMoveMemory" (Destination As DRAWITEMSTRUCT, ByVal Source As Long, ByVal Length As Long)
Private Declare Function IsBadReadPtrDRAWITEMSTRUCT Lib "kernel32" Alias "IsBadReadPtr" (ByVal lp As Long, ByVal ucb As Long) As Long
Private Declare Function IsBadWritePtrDRAWITEMSTRUCT Lib "kernel32" Alias "IsBadWritePtr" (ByVal lp As Long, ByVal ucb As Long) As Long

Private mRect As APIRect
Private mCtlType As OwnerDrawItemTypes
Public ControlId As Long
Public ItemId As Long
Public Action As OwnerDrawItemActions
Public ItemState As OwnerDrawItemStates
Private mHwnd As Long
Private mHdc As Long

Private CreatedOK As Boolean


Public Property Let ControlType(ByVal newControlType As OwnerDrawItemTypes)

mCtlType = newControlType

End Property

'\\ --[CreateFromPointer]---------------------------------------------
'\\ Fills this DRAWITEMSTRUCT object from the location poiunted to by
'\\ lpDRAWITEMSTRUCT
'\\ VB.NET Porting note: This function should be replaced with an override
'\\ of the New() for correctness
'\\ ----------------------------------------------------------------------------------------
'\\ You have a royalty free right to use, reproduce, modify, publish and mess with this code
'\\ I'd like you to visit http://www.merrioncomputing.com for updates, but won't force you
'\\ ----------------------------------------------------------------------------------------
Public Function CreateFromPointer(lpDRAWITEMSTRUCT As Long) As Boolean

Dim ftThis As DRAWITEMSTRUCT

CreatedOK = False

If Not IsBadReadPtrDRAWITEMSTRUCT(lpDRAWITEMSTRUCT, Len(ftThis)) Then
    Call CopyMemoryDRAWITEMSTRUCT(ftThis, lpDRAWITEMSTRUCT, Len(ftThis))
    If Err.LastDllError = 0 Then
        With ftThis
            mCtlType = .CtlType
            ControlId = .CtlID
            ItemId = .ItemId
            Action = .itemAction
            ItemState = .ItemState
            mHwnd = .hwndItem
            mHdc = .hdc
            If Err.LastDllError = 0 Then
                CreatedOK = True
            End If
        End With
    End If
End If

CreateFromPointer = CreatedOK

End Function

Public Property Get ControlType() As OwnerDrawItemTypes

    ControlType = mCtlType
    
End Property


Public Property Get DeviceContext() As ApiDeviceContext

Dim tmpDC As ApiDeviceContext

Set tmpDC = New ApiDeviceContext
tmpDC.hdc = mHdc
Set DeviceContext = tmpDC

End Property