stream

自带的:

单一

class DataBloc {
  StreamController dataBloc = StreamController();
  StreamSink get dataSink => dataBloc.sink;
}

　　

addData(){
    dataBloc.dataSink.add('addsfdb');
  }

　　

StreamBuilder(
            stream: dataBloc.dataBloc.stream,
            builder: (context, snapshot){
              if(snapshot.hasData){
                return Text('${snapshot.data}');
              }else{
                return Text('first');
              }
            },
          ),

　　

多次

class DataBloc {
  StreamController dataBloc;
  DataBloc(){
    dataBloc = StreamController.broadcast();
  }
  Stream get dataStream => dataBloc.stream;
  StreamSink get dataSink => dataBloc.sink;
}

　　

StreamBuilder(
            stream: dataBloc.dataStream,
            builder: (context, snapshot){
              if(snapshot.hasData){
                print('this first ${snapshot.data}');
                return Text('${snapshot.data}');
              }else{
                return Text('first');
              }
            },
          ),

          StreamBuilder(
            stream: dataBloc.dataStream,
            builder: (context, snapshot){
              if(snapshot.hasData){
                print('this seconds. ${snapshot.data}');
                return Text('${snapshot.data}');
              }else{
                return Text('second');
              }
            },
          ),

　　

 addData(){
    dataBloc.dataSink.add('addsfdb');
  }

　　

rxdart:

class DataBloc {
  PublishSubject dataBloc = PublishSubject();
}

　　

StreamBuilder(
            stream: dataBloc.dataBloc.stream,
            builder: (context, snapshot){
              if(snapshot.hasData){
                print('this first ${snapshot.data}');
                return Text('${snapshot.data}');
              }else{
                return Text('first');
              }
            },
          ),

          StreamBuilder(
            stream: dataBloc.dataBloc.stream,
            builder: (context, snapshot){
              if(snapshot.hasData){
                print('this seconds. ${snapshot.data}');
                return Text('${snapshot.data}');
              }else{
                return Text('second');
              }
            },
          ),

　　

addData(){
    dataBloc.dataBloc.add('xyz');
  }