3.1.Flutter-接口动画插件配合EventBus使用

1.EventBus = flutter2.0.6

//定义一个top-level（全局）变量，页面引入该文件后可以直接使用bus
var eBus = new EventBus();

//订阅者回调签名
typedef void EventCallback(arg);

class EventBus {
  //私有构造函数
  EventBus._internal();

  //保存单例
  static EventBus _singleton = new EventBus._internal();

  //工厂构造函数
  factory EventBus() => _singleton;

  //保存事件订阅者队列，key:事件名(id)，value: 对应事件的订阅者队列
  var _emap = new Map<Object, List<EventCallback>>();

  //添加订阅者
  void on(eventName, EventCallback f) {
    if (eventName == null || f == null) return;
    _emap[eventName] ??= new List<EventCallback>();
    _emap[eventName].add(f);
  }

  //移除订阅者
  void off(eventName, EventCallback f) {
    var list = _emap[eventName];
    if (eventName == null || list == null) return;
    if (f == null) {
      _emap[eventName] = null;
    } else {
      list.remove(f);
    }
  }

  //触发事件，事件触发后该事件所有订阅者会被调用
  void emit(eventName, [arg]) {
    var list = _emap[eventName];
    if (list == null) return;
    int len = list.length - 1;
    //反向遍历，防止在订阅者在回调中移除自身带来的下标错位
    for (var i = len; i > -1; --i) {
      list[i](arg);
    }
  }
}

1.EventBus = flutter3.7.0

//定义一个top-level（全局）变量，页面引入该文件后可以直接使用bus
var eBus = EventBus();

//订阅者回调签名
typedef EventCallback = void Function(dynamic arg);

class EventBus {
  //私有构造函数
  EventBus._internal();

  //保存单例
  static final EventBus _singleton = EventBus._internal();

  //工厂构造函数
  factory EventBus() => _singleton;

  //保存事件订阅者队列，key:事件名(id)，value: 对应事件的订阅者队列
  final _eMap = <Object, List<EventCallback>>{};

  //添加订阅者
  void on(eventName, EventCallback f) {
    if (eventName == null) return;
    _eMap[eventName] ??= <EventCallback>[];
    _eMap[eventName]!.add(f);
  }

  //移除订阅者
  void off(eventName, EventCallback f) {
    var list = _eMap[eventName];
    if (eventName == null || list == null) return;
    list.remove(f);
    if (_eMap[eventName]!.isEmpty) _eMap.remove(eventName);
  }

  //触发事件，事件触发后该事件所有订阅者会被调用
  void emit(eventName, [arg]) {
    var list = _eMap[eventName];
    if (list == null) return;
    int len = list.length - 1;
    //反向遍历，防止在订阅者在回调中移除自身带来的下标错位
    for (var i = len; i > -1; --i) {
      list[i](arg);
    }
  }
}

2.接口动画

//接口监听
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:imes_base_plugins/EventBus.dart';
import 'package:imes_base_plugins/common/logs.dart';

//监听接口
EventCallback dioErrorEvent;
//接口提示-保证只进行一次
bool showNetwork = false;
//是否启用动画
bool isShowAnimation = true;

///0 开启事件线-接口监听
onDioNetworkListener(BuildContext context) {
  //网络错误时
  dioErrorEvent = (arg) {
    if (isShowAnimation) _dismissEndProgressDialog(context);
  };
  eBus.on("DioError", dioErrorEvent);
}

///0 关闭事件线-接口监听
offDioNetworkListener() {
  eBus.off("DioError", dioErrorEvent);
}

/*
用法:
bool isDio = startDioNetworkAnimation(context);
logs("dio是否执行接口: $isDio");
if (isDio == false) return Future.value(false);
* */

///1 接口开启动画  milliseconds=100:init,milliseconds500:then
bool startDioNetworkAnimation(
  BuildContext context, {
  bool isShow = true, //默认开启动画
  bool barrierDismissible = false, //false:不允许点击空白关闭动画
  bool willPopScope = true, //true:允许点击硬件返回键关闭动画
}) {
  if (showNetwork == false) {
    showNetwork = true;
    isShowAnimation = isShow;
    if (isShow) _showStartProgressDialog(context, barrierDismissible: barrierDismissible, willPopScope: willPopScope);
    return true;
  }
  return false;
}

///1 网络刷新动画
Future _showStartProgressDialog(
  BuildContext context, {
  bool barrierDismissible,
  bool willPopScope,
}) async {
  var dialog = showDialog(
    barrierDismissible: barrierDismissible,
    context: context,
    builder: (BuildContext context) {
      return WillPopScope(
        onWillPop: () {
          logs("2接口结束...$showNetwork");
          if (willPopScope) showNetwork = false;
          return Future.value(willPopScope);
        },
        child: Scaffold(
          backgroundColor: Colors.transparent,
          body: Center(
            child: Container(
              height: 56,
              width: 56,
              child: CircularProgressIndicator(),
            ),
          ),
        ),
      );
    },
  );
  logs("0接口开始...");
  return dialog;
}

///2 接口关闭动画
bool endDioNetworkAnimation(
  BuildContext context, {
  bool isShow = true, //默认开启动画
  int milliseconds = 0,
}) {
  if (isShow == false) showNetwork = false;
  isShowAnimation = isShow;
  if (isShow) _dismissEndProgressDialog(context, milliseconds: milliseconds);
  return true;
}

///2 隐藏刷新动画
_dismissEndProgressDialog(
  BuildContext context, {
  int milliseconds = 0,
}) {
  //
  if (showNetwork == false) return;
  showNetwork = false;
  logs("1接口结束...$showNetwork");
  //
  if (milliseconds == 0) {
    Navigator.of(context).pop();
  } else {
    Future.delayed(Duration(milliseconds: milliseconds), () {
      Navigator.of(context).pop();
    });
  }
}