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BinaryReader.Read Method (Char[], Int32, Int32)

Reads count characters from the stream with index as the starting point in the character array.

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

public virtual int Read(
	char[] buffer,
	int index,
	int count
)

Parameters

buffer
Type: System.Char[]

The buffer to read data into.

index
Type: System.Int32

The starting point in the buffer at which to begin reading into the buffer.

count
Type: System.Int32

The number of characters to read.

Return Value

Type: System.Int32
The total number of characters read into the buffer. This might be less than the number of characters requested if that many characters are not currently available, or it might be zero if the end of the stream is reached.

ExceptionCondition
ArgumentException

The buffer length minus index is less than count.

-or-

The number of decoded characters to read is greater than count. This can happen if a Unicode decoder returns fallback characters or a surrogate pair.

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

index or count is negative.

ObjectDisposedException

The stream is closed.

IOException

An I/O error occurs.

BinaryReader does not restore the file position after an unsuccessful read.

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

The following example shows how to read and write data using memory as a backing store. This example displays a list of invalid file path characters to the console. Although the code tries to display a list of all invalid file path characters, not all of the characters are within the displayable set of characters. Because the list of invalid characters can vary based on the system, output for this code may also vary.

using System;
using System.IO;

class BinaryRW
{
    static void Main()
    {
        char[] invalidPathChars = Path.InvalidPathChars;
        MemoryStream memStream = new MemoryStream();
        BinaryWriter binWriter = new BinaryWriter(memStream);

        // Write to memory.
        binWriter.Write("Invalid file path characters are: ");
        binWriter.Write(
            Path.InvalidPathChars, 0, Path.InvalidPathChars.Length);

        // Create the reader using the same MemoryStream  
        // as used with the writer.
        BinaryReader binReader = new BinaryReader(memStream);

        // Set Position to the beginning of the stream.
        memStream.Position = 0;

        // Read the data from memory and write it to the console.
        Console.Write(binReader.ReadString());
        int arraySize = (int)(memStream.Length - memStream.Position);
        char[] memoryData = new char[arraySize];
        binReader.Read(memoryData, 0, arraySize);
        Console.WriteLine(memoryData);
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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