StreamReader.ReadToEnd Method

Definition

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

public override string ReadToEnd ();

Returns

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 ("").

Exceptions

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

An I/O error occurs.

Examples

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());
        }
    }
}

Remarks

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.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP 10.0

See also