取得TextBox 某一行的字串

　　这是使用EM_GETLINE message来做，比较奇特的是lParam是指向一个字串所在的位置，但是该字串传入时，前两个Byte要存该字串允许的最大长度。

'以下在Form需一个TextBox，并设定MultiLine = True, 一个Command ButtonPrivate Sub Command1_Click()Dim str5 As Stringstr5 = GetaLine(Text1,1)　'取得第二行的字串，以0为基底End Sub'以下在.BasOption ExplicitConst EM_GETLINE = &HC4Declare Function SendMessage Lib "user32" Alias "SendMessageA" _　　　　(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _　　　　 lParam As Any) As LongPublic Function GetaLine(Text1 As TextBox, ByVal ntx As Long) As StringDim str5(255) As Byte '如果您的字串  255 byte请自行增加该Byte ArrayDim str6 As String, i As Longstr5(0) = 255 '字串的前两个Byte存该字串的最大长度str5(0) = 255i = SendMessage(Text1.hwnd, EM_GETLINE, ntx, str5(0))If i = 0 Then　　GetaLine = ""Else　　str6 = StrConv(str5, vbUnicode)　　GetaLine = Left(str6, InStr(1, str6, Chr(0)) - 1)End IfEnd Function