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BinaryReader.ReadChars Method

Reads the specified number of characters from the current stream, returns the data in a character array, and advances the current position in accordance with the Encoding used and the specific character being read from the stream.

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

public virtual char[] ReadChars(
	int count
)

Parameters

count
Type: System.Int32

The number of characters to read.

Return Value

Type: System.Char[]
A character array containing data read from the underlying stream. This might be less than the number of characters requested if the end of the stream is reached.

ExceptionCondition
ArgumentException

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.

ObjectDisposedException

The stream is closed.

IOException

An I/O error occurs.

ArgumentOutOfRangeException

count is negative.

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

When reading from network streams, in some rare cases, the ReadChars method might read an extra character from the stream if the BinaryReader was constructed with Unicode encoding. If this occurs, you can use the ReadBytes method to read a fixed-length byte array, and then pass that array to the ReadChars method.

The following code example shows how to read and write data using memory as a backing store.

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);

        // 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());
        Console.WriteLine(binReader.ReadChars(
            (int)(memStream.Length - memStream.Position)));
    }
}

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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