OpenText Method

File.OpenText Method (String)


Opens an existing UTF-8 encoded text file for reading.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

public static StreamReader OpenText(
	string path


Type: System.String

The file to be opened for reading.

Return Value

Type: System.IO.StreamReader

A StreamReader on the specified path.

Exception Condition

The caller does not have the required permission.


path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by InvalidPathChars.


path is null.


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.


The specified path is invalid, (for example, it is on an unmapped drive).


The file specified in path was not found.


path is in an invalid format.

This method is equivalent to the StreamReader(String) constructor overload.

The path parameter is permitted to specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see GetCurrentDirectory.

For a list of common I/O tasks, see Common I/O Tasks.

The following example opens a text file for reading.

using System;
using System.IO;
using System.Text;

class Test 
    public static void Main() 
        string path = @"c:\temp\MyTest.txt";

        if (!File.Exists(path)) 
            // Create the file.
            using (FileStream fs = File.Create(path)) 
                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);

        // Open the stream and read it back.
        using (StreamReader sr = File.OpenText(path)) 
            string s = "";
            while ((s = sr.ReadLine()) != null) 

for reading from the specified file. Associated enumeration: FileIOPermissionAccess.Read

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Return to top
© 2015 Microsoft