VB ListBox 添加横向滚动条

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
Private Const LB_SETHORIZONTALEXTENT = &H194
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Private Sub setListWidth()
        '如果列表框不够宽，则增加水平滚动条
        Dim i     As Integer
        Dim List_MaxL     As Integer
        '获得选项内容的最大长度
        For i = 0 To List1.ListCount - 1
                ''让list_maxl中保存最长的一条字串
                If Len(List1.List(i)) > List_MaxL Then
                        List_MaxL = Len(List1.List(i)) + 2
                End If
        Next i
        '判断是否内容显示不完全，如果是则添加水平滚动条
        If Me.TextWidth("AA ") * List_MaxL > List1.Width Then
                SendMessage List1.hwnd, LB_SETHORIZONTALEXTENT, Me.TextWidth("a") * List_MaxL, ByVal 0&
        End If
End Sub

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Private Sub Form_Load()
      Dim i     As Integer
      '为ListBox控件添加选项
      For i = 0 To 100
            List1.AddItem ("这是，最据jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj：（第   " + CStr(i)) & "行） "
           'List1.AddItem   ( "（第   "   +   CStr(i))   &   "行） "
      Next i
     ' 设置窗体坐标尺度模式和字体大小
      Me.ScaleMode = vbPixels
      Me.FontSize = List1.FontSize
     设置列表框的水平滚动条
      Call setListWidth
End Sub


'方法二：-----------------------------------------------------------------------------------------------

'添加 ListBox 水平滚动条-------------------------------------------------
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type

Private Declare Function DrawText Lib "user32" Alias "DrawTextA" (ByVal hdc As Long, _
ByVal lpStr As String, ByVal nCount As Long, lpRect As RECT, ByVal wFormat As Long) As Long
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 LB_SETHORIZONTALEXTENT = &H194
Const DT_CALCRECT = &H400



Public Function ListTextWidth(ByRef lstThis As ListBox) As Long '获取最长项目的象素长度值
Dim i As Long
Dim tR As RECT
Dim lW As Long
Dim lWidth As Long
Dim lHDC As Long
With lstThis.Parent.Font
.Name = lstThis.Font.Name
.Size = lstThis.Font.Size
.Bold = lstThis.Font.Bold
.Italic = lstThis.Font.Italic
End With
lHDC = lstThis.Parent.hdc
For i = 0 To lstThis.ListCount - 1 '遍历所有的列表项以找到最长的项
DrawText lHDC, lstThis.List(i), -1, tR, DT_CALCRECT
lW = tR.Right - tR.Left + 8
If lW > lWidth Then lWidth = lW
Next
ListTextWidth = lWidth + 20 '返回最长列表项的长度（像素）
End Function

Private Sub Form_Load()
'设置 List 横向滚动条
dim l As Long
l = ListTextWidth(ltCol)
SendMessage ltCol.hwnd, LB_SETHORIZONTALEXTENT, l, 0

End Sub