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StreamReader.ReadToEnd Method

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

[Visual Basic]
Overrides Public Function ReadToEnd() As String
[C#]
public override string ReadToEnd();
[C++]
public: String* ReadToEnd();
[JScript]
public override function ReadToEnd() : String;

Return Value

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 the empty string("").

Exceptions

Exception Type Condition
OutOfMemoryException There is insufficient memory to allocate a buffer for the returned string.
IOException An I/O error occurs.

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 Read(Char[], Int32, Int32), 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 and should be avoided.

Note than 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 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. Since the position of the reader in the stream cannot be changed, the characters already read are unrecoverable, and can be accessed only by reinitializing the StreamReader. If the initial position within the stream is unknown or the stream does not support seeking, the underlying Stream also needs to be reinitialized.

To avoid such a situation and produce robust code you should use the Read method and store the read characters in a preallocated buffer.

For an example of using this method, see the Example section below. The following table lists examples of other typical or related I/O tasks.

To do this... See the example in this topic...
Create a text file. Writing Text to a File
Write to a text file. Writing Text to a File
Read from a text file. Reading Text from a File
Append text to a file. Opening and Appending to a Log File

File.AppendText

FileInfo.AppendText

Get the size of a file. FileInfo.Length
Get the attributes of a file. File.GetAttributes
Set the attributes of a file. File.SetAttributes
Determine if a file exists. File.Exists
Read from a binary file. Reading and Writing to a Newly Created Data File
Write to a binary file. Reading and Writing to a Newly Created Data File

Example

[Visual Basic, C#, C++] The following example reads all the way to the end of a file in one operation.

[Visual Basic] 
Imports System
Imports System.IO
Imports System.Text

Public Class Test

    Public Shared Sub Main()
        Dim path As String = "c:\temp\MyTest.txt"

        Try
            If File.Exists(path) Then
                File.Delete(path)
            End If

            Dim sw As StreamWriter = New StreamWriter(path)
            sw.WriteLine("This")
            sw.WriteLine("is some text")
            sw.WriteLine("to test")
            sw.WriteLine("Reading")
            sw.Close()

            Dim sr As StreamReader = New StreamReader(path)

            'This allows you to do one Read operation.
            Console.WriteLine(sr.ReadToEnd())
            sr.Close()
        Catch e As Exception
            Console.WriteLine("The process failed: {0}", e.ToString())
        End Try
    End Sub
End Class

[C#] 
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());
        }
    }
}

[C++] 
#using <mscorlib.dll>

using namespace System;
using namespace System::IO;

int main() {
    String* path = S"c:\\temp\\MyTest.txt";

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

        StreamWriter* sw = new StreamWriter(path);
        try {
            sw->WriteLine(S"This");
            sw->WriteLine(S"is some text");
            sw->WriteLine(S"to test");
            sw->WriteLine(S"Reading");
        } __finally {
            if (sw) __try_cast<IDisposable*>(sw)->Dispose();
        }

        StreamReader* sr = new StreamReader(path);
        try {
            //This allows you to do one Read operation.
            Console::WriteLine(sr->ReadToEnd());
        } __finally {
            if (sr) __try_cast<IDisposable*>(sr)->Dispose();
        }
    } catch (Exception* e) {
        Console::WriteLine(S"The process failed: {0}", e);
    }
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

StreamReader Class | StreamReader Members | System.IO Namespace | Working with I/O | Reading Text from a File | Writing Text to a File

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