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Read up to a line of data from the socket and returns it in a
string buffer.
Syntax
object.ReadLine( Handle, Buffer,
[Length] )
Parameters
- Handle
- An integer value that specifies the handle to the client
session.
- Buffer
- 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.
- Length
- 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.
Remarks
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
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