Send Method

Description

Send data after a connection is established. The Send event fires when Data is accepted by the system buffers. The SendBufferCount property indicates the number of bytes that have been submitted but have not yet been accepted by the system buffers.

Syntax

Visual Basic
Public Function Send( _ ByRef Data As Variant, _ Optional ByVal LimitCount As Long = 0 _ ) As Long

Visual Basic

Public Function Send( _
   ByRef Data As Variant, _
   Optional ByVal LimitCount As Long = 0 _
) As Long

Parameters

Data: String, Byte, or Byte array. Data to be sent.
LimitCount: Number of bytes to send (limits a String or Byte array to LimitCount bytes).

Return Value

Number of bytes submitted.

Remarks

You can use this method only when the State property is tcpConnected; otherwise, a ptNotConnected error is generated.

Data can be provided in two ways:

A String is converted from Unicode to US_ASCII according to the default code table. Each 16-bit Unicode character is translated to an 8-bit byte. This is a convenient coding mechanism for many environments, but is not as efficient as sending a Byte array.
A Byte or Byte array is sent as presented, with no translation.

If LimitCount is specified and is greater than 0, then the number of bytes sent is limited to LimitCount. For example, if a Byte array of length 8192 contains only 100 bytes that the user wants to send, then a LimitCount of 100 can be used to override the default behavior, which would be to send the entire 8192 bytes (the length of the array).

This method can be invoked as blocking or non-blocking, depending on the value of the Timeout property. When performing blocked method calls, the Blocked property may be checked to verify the control is not busy executing another method. If the Timeout property is positive, this method blocks until the system accepts the data for sending (the SendBufferCount property decrements to 0) or the timeout period expires.

Any IAC character (ASCII 255) is doubled up according to the protocol specification. Any CR character (ASCII 13) not followed by a LF character (ASCII 10) has a NULL inserted after it according to the protocol specification. The reciprocal operation is applied to received data. The user should use CR/LF (ASCII 13 and ASCII 10) to terminate each line.

Error Codes
The Send method may generate the following error codes (refer to the ErrorConstants topic for a complete list of error codes):

ptBlocked
ptConnectionAborted
ptConnectionReset
ptInvalidParam1 (Data is not a String, Byte, or Byte array)
ptNetworkDown
ptNetworkReset
ptNoBufferSpace
ptNotConnected
ptTimeout

Example

Example (C#)