android开发分享Flutter 实现下拉刷新上拉加载的示例代码

  dependencies:   pull_to_refresh: ^1.5.7

  import 'package:pull_to_refresh/pull_to_refresh.dart';

  class _myhomepagestate extends state<myhomepage> {   list<string> items = ["1", "2", "3", "4", "5", "6", "7", "8"];   refreshcontroller _refreshcontroller =   refreshcontroller(initialrefresh: false);     void _onrefresh() async {    // monitor network fetch    await future.delayed(duration(milliseconds: 1000));    // if failed,use refreshfailed()    _refreshcontroller.refreshcompleted();   }     void _onloading() async {    // monitor network fetch    await future.delayed(duration(milliseconds: 1000));    // if failed,use loadfailed(),if no data return,use loadnodata()    items.add((items.length + 1).tostring());    if (mounted) setstate(() {});    _refreshcontroller.loadcomplete();   }     @override   widget build(buildcontext context) {    return scaffold(     body: smartrefresher(      enablepulldown: true,      enablepullup: true,      header: waterdropheader(),      footer: customfooter(       builder: (buildcontext context, loadstatus mode) {        widget body;        if (mode == loadstatus.idle) {         body = text("pull up load");        } else if (mode == loadstatus.loading) {         body = circularprogressindicator();        } else if (mode == loadstatus.failed) {         body = text("load failed!click retry!");        } else if (mode == loadstatus.canloading) {         body = text("release to load more");        } else {         body = text("no more data");        }        return container(         height: 55.0,         child: center(child: body),        );       },      ),      controller: _refreshcontroller,      onrefresh: _onrefresh,      onloading: _onloading,      child: listview.builder(       itembuilder: (c, i) => card(child: center(child: text(items[i]))),       itemextent: 100.0,       itemcount: items.length,      ),     ),    );   }  }