Stream.CopyTo Method

Definition

Namespace:

System.IO

Assembly:

System.Runtime.dll

Reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.

Overloads

CopyTo(Stream)	Reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.
CopyTo(Stream, Int32)	Reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Both streams positions are advanced by the number of bytes copied.

CopyTo(Stream)

Source:

Stream.cs

Reads the bytes from the current stream and writes them to another stream. Both streams positions are advanced by the number of bytes copied.

public:
 void CopyTo(System::IO::Stream ^ destination);

public void CopyTo (System.IO.Stream destination);

member this.CopyTo : System.IO.Stream -> unit

Public Sub CopyTo (destination As Stream)

Parameters

destination

Stream

The stream to which the contents of the current stream will be copied.

Exceptions

ArgumentNullException

destination is null.

NotSupportedException

The current stream does not support reading.

-or-

destination does not support writing.

ObjectDisposedException

Either the current stream or destination were closed before the CopyTo(Stream) method was called.

IOException

An I/O error occurred.

Examples

The following example copies the contents of a FileStream to a MemoryStream.

// Create the streams.
MemoryStream destination = new MemoryStream();

using (FileStream source = File.Open(@"c:\temp\data.dat",
    FileMode.Open))
{

    Console.WriteLine("Source length: {0}", source.Length.ToString());

    // Copy source to destination.
    source.CopyTo(destination);
}

Console.WriteLine("Destination length: {0}", destination.Length.ToString());

' Create the streams.
Dim destination As New MemoryStream()

Using source As FileStream = File.Open("c:\temp\data.dat", _
                                       FileMode.Open)
    Console.WriteLine("Source length: {0}", source.Length.ToString())

    ' Copy source to destination.
    source.CopyTo(destination)

End Using
Console.WriteLine("Destination length: {0}", destination.Length.ToString())

Remarks

Copying begins at the current position in the current stream, and does not reset the position of the destination stream after the copy operation is complete.

CopyTo(Stream, Int32)

Source:

Stream.cs

Reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Both streams positions are advanced by the number of bytes copied.

public:
 virtual void CopyTo(System::IO::Stream ^ destination, int bufferSize);

public virtual void CopyTo (System.IO.Stream destination, int bufferSize);

abstract member CopyTo : System.IO.Stream * int -> unit
override this.CopyTo : System.IO.Stream * int -> unit

Public Overridable Sub CopyTo (destination As Stream, bufferSize As Integer)

Parameters

destination

Stream

The stream to which the contents of the current stream will be copied.

bufferSize

Int32

The size of the buffer. This value must be greater than zero. The default size is 81920.

Exceptions

ArgumentNullException

destination is null.

ArgumentOutOfRangeException

bufferSize is negative or zero.

NotSupportedException

The current stream does not support reading.

-or-

destination does not support writing.

ObjectDisposedException

Either the current stream or destination were closed before the CopyTo(Stream) method was called.

IOException

An I/O error occurred.

Remarks

Copying begins at the current position in the current stream, and does not reset the position of the destination stream after the copy operation is complete.