继续上一节，继续读写代码的编写。
为了简化操作，所有的Encoding均采用Encoding.Default。
读取方法3；
直接使用StreamReader（参数1：要打开的文件全路径，参数2：编码格式）
读取方式：循环读取一行文本
读取方式：循环读取一行文本
Private Sub readText3(ByVal filename As String)
Dim textContent As String
Dim sr As New StreamReader(filename,Encoding.Default)
Do
textContent = sr.ReadLine()
If IsNothing(textContent) Then Exit Do
txtFile.Text &= textContent & ControlChars.CrLf
Loop While True
sr.Close()
End Sub
写入方法3：
Private Sub writeText3(ByVal filename As String)
Dim textContent As String = txtFile.Text
Dim sw As New StreamWriter(filename,False)
Dim arrTextContent() As String = textContent.Split(ControlChars.CrLf)
For i As Integer = 0 To arrTextContent.Length - 1
sw.WriteLine(arrTextContent(i))
Next
sw.Close()
End Sub使用时会发现，最后多写了一个回车。因为使用split的时候最后一个ControlChars.CrLf多带来了一个空字符串。请自行改正。
读取方法4：
Private Sub readText4(ByVal filename As String)
Dim textContent As String
Dim buffer() As Char
Dim lenRead As Long
Dim fs As New FileStream(filename,FileMode.OpenOrCreate,FileAccess.Read)
lenRead = fs.Length
Dim sr As New StreamReader(fs,Encoding.Default)
ReDim buffer(lenRead - 1)
sr.Read(buffer,lenRead)
sr.Close()
fs.Close()
textContent = New String(buffer)
txtFile.Text = textContent
End Sub
写入方法4：
Private Sub writeText4(ByVal filename As String)
Dim textContent As String = txtFile.Text
Dim lenWrite As Long
Dim fs As New FileStream(filename,FileAccess.ReadWrite)
lenWrite = textContent.Length
Dim sw As New StreamWriter(fs,Encoding.Default,lenWrite - 1)
sw.WriteLine(textContent)
sw.Close()
fs.Close()
End Sub
由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。
学习更多vb.net知识，请参看 vb.net 教程 目录