使用ToolTip来解决超长文字的显示问题是不错的方案，下面给出了例子的代码。
Option Explicit
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_ITEMFROMPOINT = &H1A9
Private Sub Form_Load()
Dim i As Integer
For i = 0 To 5
List1.AddItem "ListItem字符串超长超长超长超长超长咯 " & i
Next
End Sub
Private Sub List1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim lParam As Long
Dim lResult As Long
lParam = (CInt(Y / Screen.TwipsPerPixelY) * 2 ^ 16) + CInt(X / Screen.TwipsPerPixelX)
lResult = SendMessage(List1.hwnd, LB_ITEMFROMPOINT, 0, ByVal lParam)
If lResult < 0 Or lResult > 32767 Then
List1.ToolTipText = ""
Exit Sub
End If
Dim nIndex As Integer
nIndex = CInt(lResult)
List1.ToolTipText = List1.List(nIndex)
End Sub
在 Win2000 + VB6 中调试通过