ReadLine Method  

Read up to a line of data from the socket and returns it in a string buffer.


object.ReadLine( Handle, Buffer, [Length] )


An integer value that specifies the handle to the client session.
A buffer that the data will be stored in. If the variable is a String then the data will be returned as a string of characters. This is the most appropriate data type to use if the server is sending data that consists of printable characters. If the server is sending binary data, it is recommended that a Byte array be used instead. This parameter must be passed by reference.
A numeric value which specifies the number of bytes to read. Its maximum value is 231-1 = 2147483647. This argument is required to be present for string data. If a value is specified for this argument for other permissible types of data, and it is less than number of bytes that is determined by the control, then Length will override the internally computed value. If the argument is omitted, then the maximum number of bytes to read is determined by the size of the buffer.

Return Value

This method will return True if a line of data has been read. If an error occurs or there is no more data available to read, then the method will return False. It is possible for data to be returned in the string buffer even if the return value is False. Applications should check the length of the string after the method returns to determine if any data was copied into the buffer. For example, if a timeout occurs while the method is waiting for more data to arrive on the socket, it will return zero; however, data may have already been copied into the string buffer prior to the error condition. It is the responsibility of the application to process that data, regardless of the function return value.


The ReadLine method reads data from the socket up to the specified number of bytes or until an end-of-line character sequence is encountered. Unlike the Read method which reads arbitrary bytes of data, this function is specifically designed to return a single line of text data in a string variable. When an end-of-line character sequence is encountered, the function will stop and return the data up to that point; the string will not contain the carriage-return or linefeed characters.

There are some limitations when using the ReadLine method. The method should only be used to read text, never binary data. In particular, it will discard nulls, linefeed and carriage return control characters. This method will force the thread to block until an end-of-line character sequence is processed, the read operation times out or the remote host closes its end of the socket connection.

The Read and ReadLine methods can be intermixed, however be aware that the Read method will consume any data that has already been buffered by the ReadLine method and this may have unexpected results.

See Also

CodePage Property, IsReadable Property, Peek Method, Read Method, Write Method, WriteLine Method