SerialPort.Read Method (Byte, Int32, Int32)
Reads a number of bytes from the SerialPort input buffer and writes those bytes into a byte array at the specified offset.
Assembly: System (in System.dll)
The byte array to write the input to.
The offset in buffer at which to write the bytes.
The maximum number of bytes to read. Fewer bytes are read if count is greater than the number of bytes in the input buffer.
Return ValueType: System.Int32
The number of bytes read.
The buffer passed is null.
The specified port is not open.
The offset or count parameters are outside a valid region of the buffer being passed. Either offset or count is less than zero.
offset plus count is greater than the length of the buffer.
No bytes were available to read.
If it is necessary to switch between reading text and reading binary data from the stream, select a protocol that carefully defines the boundary between text and binary data, such as manually reading bytes and decoding the data.
Because the SerialPort class buffers data, and the stream contained in the BaseStream property does not, the two might conflict about how many bytes are available to read. The BytesToRead property can indicate that there are bytes to read, but these bytes might not be accessible to the stream contained in the BaseStream property because they have been buffered to the SerialPort class.
Themethod does not block other operations when the number of bytes read equals count but there are still unread bytes available on the serial port.
Available since 2.0