vb.net中如何读取文本框textbox中指定行的内容？

[mai51]

一个很长的英文句子，放在textbox中时，被分成几行，请问如何读取第N行的内容（注意：文本中并没有分行符，另外环境是在vb.net中)，谢谢！

[mai51]

由于文本框textbox宽度有限，自然分成了几行

[appleller]

是不是可以根据字符串长度结合textbox宽度来计算

[it_gz_xi]

那楼主可以试试substring

[lrjt1980]

不是有属性设置吗

[martinuk]

不用多说啦， 用下面的code就好了。 给点分吧，呵呵（^_^)

 Private Overloads Declare Auto Function SendMessage Lib "user32" ( _
ByVal hwnd As IntPtr, _
ByVal wMsg As Int32, _
ByVal wParam As Int32, _
ByVal lParam As String _
) As Int32


    Private Overloads Declare Auto Function SendMessage Lib "user32" ( _
    ByVal hwnd As IntPtr, _
    ByVal wMsg As Int32, _
    ByVal wParam As Int32, _
    ByVal lParam As Int32 _
    ) As Int32


    Private Const EM_GETLINE As Int32 = &HC4

    Private Const EM_GETLINECOUNT As Int32 = &HBA

    Private Const MAX_CHAR_PER_LINE As Int32 = &H100

    Private Const EM_LINELENGTH As Int32 = &HC1

    Private Const EM_LINEINDEX As Int32 = &HBB

    Private Function GetLine(ByVal Text As TextBoxBase, ByVal Line As Integer) As String
        Dim dwLineStart As Int32 = SendMessage(Text.Handle, EM_LINEINDEX, Line, 0)
        Dim dwLineLen As Integer = SendMessage(Text.Handle, EM_LINELENGTH, dwLineStart, 0)

        Dim Buff As String = Chr(dwLineLen And &HFF) & Chr(dwLineLen / &H100) & Space(dwLineLen)

        Dim dwLen As Int32 = SendMessage(Text.Handle, EM_GETLINE, Line, Buff)

        GetLine = Strings.Left(Buff, dwLen)

    End Function
    Private Sub Button3_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim g As Graphics = TextBox1.CreateGraphics()
        Dim w As Integer = CType(g.MeasureString(TextBox1.Text, TextBox1.Font).Width, Integer)
        Dim s As String = GetLine(TextBox1, 0)
        MsgBox(s)
    End Sub

[martinuk]

BTW, 这两行
Dim g As Graphics = TextBox1.CreateGraphics()
Dim w As Integer = CType(g.MeasureString(TextBox1.Text, TextBox1.Font).Width, Integer)
多余可以去掉

[贝隆]

帮顶

[it_gz_xi]

楼主是怎么分成几行的？