setStringChannelCallback method
Implementation
void setStringChannelCallback(String channelName, Function callback) {
_callbackList.add(callback);
Map<String, String> map = {
MessageTag.MESSAGE_TYPE: MessageType.SET_STRING_CHANNEL_CALLBACK,
MessageTag.CHANNEL_NAME: channelName,
MessageTag.CALLBACK_INDEX: _callbackList.length.toString(),
};
_sendPort.send([map, _callbackPort.sendPort]);
}