FileStream::Read Method (array<Byte>^, Int32, Int32)

 

Reads a block of bytes from the stream and writes the data in a given buffer.

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

public:
virtual int Read(
	array<unsigned char>^ array,
	int offset,
	int count
) override

Parameters

array
Type: array<System::Byte>^

When this method returns, contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.

offset
Type: System::Int32

The byte offset in array at which the read bytes will be placed.

count
Type: System::Int32

The maximum number of bytes to read.

Return Value

Type: System::Int32

The total number of bytes read into the buffer. This might be less than the number of bytes requested if that number of bytes are not currently available, or zero if the end of the stream is reached.

Exception Condition
ArgumentNullException

array is null.

ArgumentOutOfRangeException

offset or count is negative.

NotSupportedException

The stream does not support reading.

IOException

An I/O error occurred.

ArgumentException

offset and count describe an invalid range in array.

ObjectDisposedException

Methods were called after the stream was closed.

This method overrides Read.

The offset parameter gives the offset of the byte in array (the buffer index) at which to begin reading, and the count parameter gives the maximum number of bytes to be read from this stream. The returned value is the actual number of bytes read, or zero if the end of the stream is reached. If the read operation is successful, the current position of the stream is advanced by the number of bytes read. If an exception occurs, the current position of the stream is unchanged.

The Read method returns zero only after reaching the end of the stream. Otherwise, Read always reads at least one byte from the stream before returning. If no data is available from the stream upon a call to Read, the method will block until at least one byte of data can be returned. An implementation is free to return fewer bytes than requested even if the end of the stream has not been reached.

Use BinaryReader for reading primitive data types.

Do not interrupt a thread that is performing a read operation. Although the application may appear to run successfully after the thread is unblocked, the interruption can decrease your application's performance and reliability.

For a list of common file and directory operations, see Common I/O Tasks.

The following example reads the contents from a FileStream and writes it into another FileStream.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 10
.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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