下面的函数将返回控件的文本行数,如果控件的文本为空也会返回1。 Function GetLineCount(CTextBox As TextBox) As Long GetLineCount = SendMessage(CTextBox.hWnd, EM_GETLINECOUNT, 0, 0) End Function
下面的函数将返回控件中显示的第一行的行号。 Function GetFirstVisableLine(CTextBox As TextBox) As Long GetFirstVisableLine = SendMessageBynum(CTextBox.hwnd, EM_GETFIRSTVISIBLELINE, 0, 0) End Function
下面的函数将返回控件能显示的行数。 Function GetVisibleLines(CTextBox As TextBox) As Long Dim rc As RECT Dim hDC&, lfont&, oldfont& Dim di&, lc& Dim tm As TEXTMETRIC
lc = SendMessage(CTextBox.hwnd, EM_GETRECT, 0, rc) lfont = SendMessage(CTextBox.hwnd, WM_GETFONT, 0, 0) hDC = GetDC(CTextBox.hwnd) If lfont <> 0 Then oldfont = SelectObject(hDC, lfont) di = GetTextMetrics(hDC, tm) If lfont <> 0 Then lfont = SelectObject(hDC, oldfont) GetVisibleLines = (rc.bottom - rc.top) / tm.tmHeight di = ReleaseDC(CTextBox.hwnd, hDC) End Function
下面的函数能够滚动控件,不过在滚动之前最好判断控件的文本行数和能够显示的行数,以免滚动时发生混乱。函数SendMessageBynum是一个SendMessage函数的安全声明函数,其定义与SendMessage函数完全相同,只是函数名不同。 Function ScrollTextBox(CTextBox As TextBox, nVal As Long, Optional nVertical As Boolean = True) As Long If nVertical Then ScrollTextBox = SendMessageBynum(CTextBox.hwnd, EM_LINESCROLL, 0, nVal) Else ScrollTextBox = SendMessageBynum(CTextBox.hwnd, EM_LINESCROLL, nVal, 0) End If End Function
下面的函数能够返回控件指定行的文本。SendMessageBystring与SendMessageBynum类似。 Function GetLineText(CTextBox As TextBox, LineIndex As Long) As String Dim lc&, linechar& linechar = SendMessageBynum(CTextBox.hwnd, EM_LINEINDEX, LineIndex, 0) lc = SendMessageBynum(CTextBox.hwnd, EM_LINELENGTH, linechar, 0) + 1 GetLineText = String$(lc + 2, 0) Mid$(GetLineText, 1, 1) = Chr(lc And &HFF) Mid$(GetLineText, 2, 1) = Chr(lc \ &H100) lc = SendMessageBystring(CTextBox.hwnd, EM_GETLINE, LineIndex, GetLineText) GetLineText = left(GetLineText, lc) End Function
下面的函数可以设置控件的左边距。 Public Const EM_SETMARGINS& = &HD3 Public Const EC_LEFTMARGIN& = &H1 Function SetMargins(CTextBox As TextBox, nVal As Long) As Long SetMargins = SendMessageBynum(CTextBox.hwnd, EM_SETMARGINS, EC_LEFTMARGIN, nVal) End Function
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