Add the following code to General Declarations section of Module1:
向Module1中添加如下代码:
Option Explicit
' Private Variables
Private rResize As REQSIZE ' <--- Pointer to REQSIZE Structure
Private MaskHdr As nmhdr ' <--- Pointer to nmhdr Structure
Private OldWndProc As Long
Private Const GWL_WNDPROC = (-4)
Private Const WM_USER = &H400
Private Const WM_NOTIFY = &H4E
Private Const SWP_NOMOVE = &H2
Private Const SWP_SHOWWINDOW = &H40
Private Const EM_GETEVENTMASK = (WM_USER + 59)
Private Const EM_SETEVENTMASK = (WM_USER + 69)
Private Const ENM_REQUESTRESIZE As Long = &H40000
Private Const EN_REQUESTRESIZE = &H701
' Public Variables
Public gblWidth As Long ' <--- Var Holder for Richtext Width
Public gblHeight As Long ' <--- Var Holder for Richtext Height
Public Const EM_REQUESTRESIZE = (WM_USER + 65)
Public Const VBNullPtr = 0&
Public RichWnd As Long ' <--- Var Holder for Richtext Hwnd
Private Type nmhdr
hwndFrom As Long
idfrom As Long
code As Long
End Type
Private Type rect
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Type REQSIZE
nmhdr As nmhdr
rect As rect
End Type
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hwnd As Long,ByVal wMsg As Long,ByVal wParam As Long,_
ByVal lParam As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias _
"SetWindowLongA" (ByVal hwnd As Long,ByVal nIndex As Long,_
ByVal dwNewLong As Long) As Long
Private Declare Function CallWindowProc Lib "user32" _
Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long,_
ByVal hwnd As Long,ByVal Msg As Long,_
ByVal lParam As Long) As Long
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
(Destination As Any,Source As Any,ByVal Length As Long)
Public Declare Function SetWindowPos Lib "user32" _
(ByVal hwnd As Long,ByVal hWndInsAfter As Long,ByVal x As Long,_
ByVal y As Long,ByVal cx As Long,ByVal cy As Long,_
ByVal wFlags As Long) As Long
' Call SetWindowLong to instantiate the Window Procedure by passing the
' Address of MyWndProc.
Public Sub NewWindowProc(fhWnd As Long)
On Error Resume Next
OldWndProc = SetWindowLong(fhWnd,GWL_WNDPROC,AddressOf MyWndProc)
End Sub
' Once the Hook is in place,All messages will be processed by this
' function. Test for a WM_NOTIFY and parse the lParam to search for a
' specific value. In this case we are looking for EN_REQUESTRESIZE in the
' nmhdr structure. If an EN_REQUESTRESIZE is found then grab the next
' structure(REQSIZE) from the lParam.
Public Function MyWndProc(ByVal hwnd As Long,_
ByVal Msg As Long,_
ByVal wParam As Long,_
ByVal lParam As Long) As Long
On Error Resume Next
Select Case Msg
Case WM_NOTIFY
Call CopyMemory(MaskHdr,ByVal lParam,Len(MaskHdr))
If MaskHdr.code = EN_REQUESTRESIZE Then
Call CopyMemory(rResize,Len(rResize))
If rResize.rect.Bottom < gblHeight Then
Call SetWindowPos(RichWnd,VBNullPtr,_
0,gblWidth,_
rResize.rect.Bottom,_
SWP_SHOWWINDOW Or SWP_NOMOVE)
Else
Call SetWindowPos(RichWnd,_
0,_
gblWidth,gblHeight,_
SWP_SHOWWINDOW Or SWP_NOMOVE)
End If
' By modifying 2 of the above parameters you can create an endless bottom
' Richtext control. This may be desirable if you plan to wrap the control
' and use it on a web page. To test this,comment the 'If' Statement above
' and replace it with the SetWindowPos Function call below.
' The control will now Resize itself to its actual contents.
' Call SetWindowPos(RichWnd,_
' 0,_
' gblWidth,rResize.rect.Bottom,_
' SWP_SHOWWINDOW Or SWP_NOMOVE)
End If
Case Else ' Handle other messages here.
End Select
' Reset windowproc
MyWndProc = CallWindowProc(OldWndProc,hwnd,Msg,wParam,lParam)
End Function
Public Sub ResetWindProc(hwnd As Long)
On Error Resume Next
' Call SetWindowLong to remove the Windows Hook from app.
Call SetWindowLong(hwnd,OldWndProc)
End Sub
Public Sub SetMask(fhWnd As Long)
On Error Resume Next
Dim CurrentMask As Long
Dim NewMask As Long
' Set the Event Mask to be called.
CurrentMask = SendMessage(fhWnd,EM_GETEVENTMASK,0)
NewMask = (CurrentMask Or ENM_REQUESTRESIZE)
Call SendMessage(fhWnd,EM_SETEVENTMASK,ENM_REQUESTRESIZE)
End Sub
