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

Reads the specified number of characters from the stream, starting from a specified 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 operation.

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);
    }
}


.NET Framework

Supported in: 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

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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