【转】VB 技巧一

改变 ListIndex而不发生 Click 事件

声明：

Private Declare Function SendMessage Lib _

"user32" Alias "SendMessageA" (ByVal _

hWnd As Long, ByVal wMsg As Long, ByVal _

wParam As Long, lParam As Any) As Long

Const CB_GETCURSEL = &H147

Const CB_SETCURSEL = &H14E

Const LB_SETCURSEL = &H186

Const LB_GETCURSEL = &H188

函数：

Public Function SetListIndex(lst As Control, _

ByVal NewIndex As Long) As Long

If TypeOf lst Is ListBox Then

Call SendMessage(lst.hWnd, _

LB_SETCURSEL, NewIndex, 0&)

SetListIndex = SendMessage(lst.hWnd, _

LB_GETCURSEL, NewIndex, 0&)

ElseIf TypeOf lst Is ComboBox Then

Call SendMessage(lst.hWnd, _

CB_SETCURSEL, NewIndex, 0&)

SetListIndex = SendMessage(lst.hWnd, _

CB_GETCURSEL, NewIndex, 0&)

End If

End Function

Private Declare Function SendMessage Lib _

"USER32" Alias "SendMessageA" _

(ByVal hwnd As Long, ByVal Msg As Long, _

ByVal wParam As Long, ByVal lParam As Long) As Long

Private Const CB_GETDROPPEDWIDTH = &H15F

Private Const CB_SETDROPPEDWIDTH = &H160

Private Const CB_ERR = -1

函数：

' 取得 Combo 下拉的宽度

' 可以利用该函数比例放大或缩小宽度

Public Function GetDropdownWidth(cboHwnd As Long) As Long

Dim lRetVal As Long

lRetVal = SendMessage(cboHwnd, CB_GETDROPPEDWIDTH, 0, 0)

If lRetVal <> CB_ERR Then

GetDropdownWidth = lRetVal

'单位为 pixels

Else

GetDropdownWidth = 0

End If

End Function

'设置 Combo 下拉的宽度

'单位为 pixels

Public Function SetDropdownWidth(cboHwnd As _

Long, NewWidthPixel As Long) As Boolean

Dim lRetVal As Long

lRetVal = SendMessage(cboHwnd, _

CB_SETDROPPEDWIDTH, NewWidthPixel, 0)

If lRetVal <> CB_ERR Then

SetDropdownWidth = True

Else

SetDropdownWidth = False

End If

End Function

Public Const CB_FINDSTRING = &H14C

Private Sub Combo1_Change()

Dim iStart As Integer

Dim sString As String

Static iLeftOff As Integer

iStart = 1

iStart = Combo1.SelStart

If iLeftOff <> 0 Then

Combo1.SelStart = iLeftOff

iStart = iLeftOff

End If

sString = CStr(Left(Combo1.Text, iStart))

Combo1.ListIndex = SendMessage(Combo1.hwnd, _

B_FINDSTRING, -1, ByVal CStr(Left( _

ombo1.Text, iStart)))

If Combo1.ListIndex = -1 Then

iLeftOff = Len(sString)

combo1.Text = sString

End If

Combo1.SelStart = iStart

iLeftOff = 0

End Sub

静态变量 iLeftOff 指定了字符长度。

Private Sub MyTextBox_GotFocus()

AutoSelect MyTextBox

End Sub

Sub AutoSelect(SelObject As Control)

SelObject.SelStart = 0

If TypeOf SelObject Is MaskEdBox Then

SelObject.SelLength = Len(SelObject.FormattedText)

Else

If TypeOf SelObject Is TextBox Then

SelObject.SelLength = Len(SelObject.Text)

End If

End If

End Sub