void send(
message
)

Sends an asynchronous message through this send port, to its corresponding ReceivePort.

The content of message can be: primitive values (null, num, bool, double, String), instances of SendPort, and lists and maps whose elements are any of these. List and maps are also allowed to be cyclic.

In the special circumstances when two isolates share the same code and are running in the same process (e.g. isolates created via Isolate.spawn), it is also possible to send object instances (which would be copied in the process). This is currently only supported by the dartvm. For now, the dart2js compiler only supports the restricted messages described above.

Source

/**
 * Sends an asynchronous [message] through this send port, to its
 * corresponding `ReceivePort`.
 *
 * The content of [message] can be: primitive values (null, num, bool, double,
 * String), instances of [SendPort], and lists and maps whose elements are any
 * of these. List and maps are also allowed to be cyclic.
 *
 * In the special circumstances when two isolates share the same code and are
 * running in the same process (e.g. isolates created via [Isolate.spawn]), it
 * is also possible to send object instances (which would be copied in the
 * process). This is currently only supported by the dartvm.  For now, the
 * dart2js compiler only supports the restricted messages described above.
 */
void send(var message);