FileRead and StreamReader介紹開啟檔案的幾個方法

 

以下程式碼, 由上而下分別是: 

(1) 以 File.Open 讀檔 

(2) 以 StreamReader 讀檔(此方法比較簡便) 

(3) 以 File 類別支援的 ReadAllText 方法, 讀出整個檔案內容. 

(4) StreamReader 搜尋檔案裡是否存在某個字串. 

因為程式碼都很簡單, 就不多做解釋, 請直接看以下所附的 code 應該不難了解. 

Imports System.IO

 

Public Class _03_StreamReader

 

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim theFile As FileStream = File.Open("d:\temp\asdf.txt", FileMode.Open, FileAccess.Read)

Dim rdr As StreamReader = New StreamReader(theFile)

TextBox1.Text = rdr.ReadToEnd()

rdr.Close()

theFile.Close()

End Sub

 

 

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

Dim rdr As StreamReader = File.OpenText("d:\temp\asdf.txt")

TextBox1.Text = rdr.ReadToEnd()

rdr.Close()

End Sub

 

 

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

MsgBox(File.ReadAllText("d:\temp\asdf.txt"))

End Sub

 

 

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

Dim rdr As StreamReader = File.OpenText("d:\temp\asdf.txt")

While Not rdr.EndOfStream

Dim ft As String = rdr.ReadLine()

If ft.Contains(TextBox2.Text) Then

MsgBox("Found " & TextBox2.Text & vbNewLine & ft)

End If

End While

End Sub

 

 

End Class