Question

vb.net中，如何删除指定文本文档中的指定行的内容

Answer 1

        Dim newfile As New List(Of String)
        For Each line As String In System.IO.File.ReadAllLines("TextFile1.txt")
            If Not line.StartsWith("3") Then newfile.Add(line)
        Next
        System.IO.File.WriteAllLines("TextFile1.txt", newfile)

建个集合，用System.IO.File的ReadAllLines读出所有内容，逐个判断，如果是需要的加入集合，如果是要删除的什么都不做，最后用WriteAllLines写入即可。

这里说明一下，上面那个代码是用来删除所有以3开头的文本行。

Answer 2

把文件读到内存中，按换行符生成string类型的数组，然后执行删除操作，最后写回到文件。

Answer 3

vb.net中删除指定文本文档中的指定行内容代码：
yVal 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

Answer 4

思路：逐行读出文本文档内容写入内存，当读到指定行跳过。再从内存中写入硬盘存储。

追问

怎么跳过呢，我需要通过那一行内容判断是否删除的

追答

判断用if-then continue语句就可以了，你好像不怎么编程序啊

Answer 5

就是 操作 TXT 文本 嘛 ，搜索一下就行了