如何實現在TextBox中如何得知Caret所在位置

　　

'在form中放一個textBox兩個label
Const EM_GETSEL = &HB0
Const EM_LINEFROMCHAR = &HC9
Const EM_LINEINDEX = &HBB
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
Public Sub GetCaretPos(ByVal hwnd5 As Long, LineNo As Long, ColNo As Long)
Dim i As Long, j As Long
Dim lParam As Long, wParam As Long
Dim k As Long
i = SendMessage(hwnd5, EM_GETSEL, wParam, lParam)
j = i / 2 ^ 16 '取得目前Caret所在前面有多少個byte
LineNo = SendMessage(hwnd5, EM_LINEFROMCHAR, j, 0) '取得前面有多少行
LineNo = LineNo + 1
k = SendMessage(hwnd5, EM_LINEINDEX, -1, 0)
'取得目前caret所在行前面有多少個byte
ColNo = j - k + 1
End Sub
Private Sub Form_Load()
Dim LineNo As Long, ColNo As Long
Call GetCaretPos(Text1.hwnd, LineNo, ColNo)
Label1.Caption = LineNo
Label2.Caption = ColNo
End Sub
Private Sub Text1_KeyUp(KeyCode As Integer, Shift As Integer)
Dim LineNo As Long, ColNo As Long
Call GetCaretPos(Text1.hwnd, LineNo, ColNo)
Label1.Caption = LineNo
Label2.Caption = ColNo
End Sub
Private Sub Text1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim LineNo As Long, ColNo As Long
Call GetCaretPos(Text1.hwnd, LineNo, ColNo)
Label1.Caption = LineNo
Label2.Caption = ColNo
End Sub