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StreamReader.ReadToEnd Method

Reads all characters from the current position to the end of the stream.

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

public override string ReadToEnd()

Return Value

Type: System.String
The rest of the stream as a string, from the current position to the end. If the current position is at the end of the stream, returns an empty string ("").

ExceptionCondition
OutOfMemoryException

There is insufficient memory to allocate a buffer for the returned string.

IOException

An I/O error occurs.

This method overrides TextReader.ReadToEnd.

ReadToEnd works best when you need to read all the input from the current position to the end of the stream. If more control is needed over how many characters are read from the stream, use the Read(Char[], Int32, Int32) method overload, which generally results in better performance.

ReadToEnd assumes that the stream knows when it has reached an end. For interactive protocols in which the server sends data only when you ask for it and does not close the connection, ReadToEnd might block indefinitely because it does not reach an end, and should be avoided.

Note that when using the Read method, it is more efficient to use a buffer that is the same size as the internal buffer of the stream. If the size of the buffer was unspecified when the stream was constructed, its default size is 4 kilobytes (4096 bytes).

If the current method throws an OutOfMemoryException, the reader's position in the underlying Stream object is advanced by the number of characters the method was able to read, but the characters already read into the internal ReadLine buffer are discarded. If you manipulate the position of the underlying stream after reading data into the buffer, the position of the underlying stream might not match the position of the internal buffer. To reset the internal buffer, call the DiscardBufferedData method; however, this method slows performance and should be called only when absolutely necessary.

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

The following code example reads all the way to the end of a file in one operation.

using System;
using System.IO;

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

        try 
        {
            if (File.Exists(path)) 
            {
                File.Delete(path);
            }

            using (StreamWriter sw = new StreamWriter(path)) 
            {
                sw.WriteLine("This");
                sw.WriteLine("is some text");
                sw.WriteLine("to test");
                sw.WriteLine("Reading");
            }

            using (StreamReader sr = new StreamReader(path)) 
            {
                //This allows you to do one Read operation.
                Console.WriteLine(sr.ReadToEnd());
            }
        } 
        catch (Exception e) 
        {
            Console.WriteLine("The process failed: {0}", e.ToString());
        }
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

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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