文本框属性为允许多行显示时，由于是软回车实现的分行，无法用SPLIT(TEXT1.TEXT,VBCRLF)准确地取出指定行的内容。本文利用SENDMESSAGE 系列函数，通过发送文本框消息，实现了获取包含指定字符串的行，并演示了如何获取文本框中文本总行数和任意指定行的文本内容。
'add a textbox with "multiline=true","scrollbars=2".
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 SendMessageByNum Lib "USER32" _
Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, _
ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Function SendMessageByString Lib "USER32" Alias _
"SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam _
As Long, ByVal lParam As String) As Long
Private Const EM_LINEINDEX = &HBB
Private Const EM_GETLINECOUNT = &HBA
Private Const EM_GETLINE = &HC4
Private Const EM_LINELENGTH = &HC1
Function GetLineText(ByVal txtbox As TextBox, ByVal LineIndex As Long) As String '返回指定行的内容
Dim lc As Long, linechar As Long
linechar = SendMessageByNum(txtbox.hWnd, EM_LINEINDEX, LineIndex, 0)
lc = SendMessageByNum(txtbox.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(txtbox.hWnd, EM_GETLINE, LineIndex, GetLineText)
GetLineText = Left(GetLineText, lc)
End Function
Function getlinewithstr(ByVal txtbox As TextBox, ByVal mystr As String) As String
Dim linecount As Long, temp() As String, i As Long
linecount = SendMessage(txtbox.hWnd, EM_GETLINECOUNT, 0, 0) '返回行数
ReDim temp(1 To linecount)
For i = 1 To linecount
temp(i) = "第" & i & "行：" & GetLineText(txtbox, i - 1) '添加行号
Next
getlinewithstr = Join(Filter(temp, mystr), vbCrLf) ' 字符串过滤
Erase temp
End Function
Private Sub Command1_Click()
MsgBox getlinewithstr(Text1, "CSDN"), 0, "包含“CSDN”的行"
End Sub
Private Sub Form_Load()
Dim a(25) As String, i As Long
For i = 0 To 25
a(i) = String(50, Chr(i + 97))
Next
Text1.Text = Join(a, "CSDN")
End Sub