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FileInfo.OpenText Method

Creates a StreamReader with UTF8 encoding that reads from an existing text file.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)
public StreamReader OpenText()

Return Value

Type: System.IO.StreamReader
A new StreamReader with UTF8 encoding.
ExceptionCondition
SecurityException

The caller does not have the required permission.

FileNotFoundException

The file is not found.

UnauthorizedAccessException

path is read-only or is a directory.

DirectoryNotFoundException

The specified path is invalid, such as being on an unmapped drive.

The following example reads text from a file.

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. 
//

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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