FileInfo.OpenText 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
建立一個帶有 UTF8 編碼的程式碼 StreamReader ,從現有的文字檔讀取。
public:
System::IO::StreamReader ^ OpenText();
public System.IO.StreamReader OpenText();
member this.OpenText : unit -> System.IO.StreamReader
Public Function OpenText () As StreamReader
傳回
一個 StreamReader 新的 UTF8 編碼。
例外狀況
來電者沒有所需的權限。
找不到該檔案。
Name 是唯讀或是目錄。
指定的路徑無效,例如位於未對應的磁碟驅動器上。
範例
下列範例會從檔案讀取文字。
using System;
using System.IO;
using System.Text;
class Test
{
public static void Main()
{
string path = @"c:\MyTest.txt";
FileInfo fi = new FileInfo(path);
// Check for existing file
if (!fi.Exists)
{
// Create the file.
using (FileStream fs = fi.Create())
{
Byte[] info =
new UTF8Encoding(true).GetBytes("This is some text in the file.");
// Add some information to the file.
fs.Write(info, 0, info.Length);
fs.Close();
}
}
// Open the stream and read it back.
using (StreamReader sr = fi.OpenText())
{
string s = "";
while ((s = sr.ReadLine()) != null)
{
Console.WriteLine(s);
}
}
}
}
//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//
//This is some text in the file.
//
Imports System.IO
Imports System.Text
Public Class OpenTextTest
Public Shared Sub Main()
Dim path As String = "c:\MyTest.txt"
Dim fi As New FileInfo(path)
' Check for existing file
If fi.Exists = false Then
' Create the file.
Dim fs As FileStream = fi.Create()
Dim info() As Byte = _
New UTF8Encoding(true).GetBytes("This is some text in the file.")
' Add some information to the file.
fs.Write(info, 0, info.Length)
fs.Close()
End If
' Open the stream and read it back.
Dim sr As StreamReader = fi.OpenText()
Dim s As String = ""
While sr.EndOfStream = false
s = sr.ReadLine()
Console.WriteLine(s)
End While
sr.Close()
End Sub
End Class
'This code produces output similar to the following;
'results may vary based on the computer/file structure/etc.:
'
'This is some text in the file.
'