?为何listbox控件中没有Tooltip属性?

发布网友发布时间：2024-07-03 09:33

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共2个回答

热心网友时间：2024-07-14 09:01

（1）

Const LB_GETITEMHEIGHT = &H1A1

HeightLst = SendMessage(List1.hWnd, LB_GETITEMHEIGHT, 0, 0) '得到List每项的高度，单位为像素

（2）函数获取当前鼠标所在List的哪一项

Friend Function ListIndex(ByVal lY As Single, ByVal ListCount As Integer) As Integer

Dim i%

'当前项为最顶部显示的第一项 + 鼠标所在的第n项

i = List1.TopIndex + (lY \ Screen.TwipsPerPixelY \ HeightLst)

If i > ListCount - 1 Or ListCount = 0 Then i = -1

ListIndex = i

End Function

（3）在List的MouseMove事件检查文本长度，若超过控件宽度，设置ToolTip值

Private Sub List1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)

Dim lIndex% '鼠标当前指向的索引

Static preIndex& '保留前次索引

lIndex = ListIndex(Y, List1.ListCount)

If lIndex >= 0 Then

Dim TextSize As POINTAPI

Dim lstRec As RECT

'获取list窗口位置

GetWindowRect List1.hWnd, lstRec

'获取当前文本长度

GetTextExtentPoint32 Me.hdc, List1.List(lIndex), LenB(List1.List(lIndex)), TextSize

'如果文本太长不够显示就出现tip

If TextSize.X >= List1.Width Then

List1.TooltipText=cstr(Now)

Else

List1.TooltipText=""

End If

End Sub

'相关API和结构定义
Const LB_ITEMFROMPOINT = &H1A9
Const LB_GETITEMHEIGHT = &H1A1
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Private Declare Function GetTextExtentPoint32 Lib "gdi32" Alias "GetTextExtentPoint32A" (ByVal hdc As Long, ByVal lpsz As String, ByVal cbString As Long, lpSize As POINTAPI) As Long
Private Declare Function GetWindowRect Lib "user32" (ByVal hWnd As Long, lpRect As RECT) 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
Private Declare Function SetCursorPos Lib "user32" (ByVal X As Long, ByVal Y As Long) As Long
Private Type RECT
        Left As Long
        Top As Long
        Right As Long
        Bottom As Long
End Type
Private Type POINTAPI
        x As Long
        y As Long
End Type

热心网友时间：2024-07-14 09:05

用API可以改变其宽度