抽出Model的存储类，不需要单例类

netrain_flutter_app/lib/main.dart

@@ -8,7 +8,7 @@ import 'laishanqi/layout_page.dart';
 import 'laishanqi/netrain/user/loginPage.dart';
 import 'laishanqi/netrain/user/RegisterPage.dart';
 import 'laishanqi/photo.dart';
-import 'zhangfeng/UserData.dart';
+import 'zhangfeng/UserModel.dart';
 
 import 'zhangfeng/LoginPage.dart';
 
@@ -16,7 +16,7 @@ void main() {
   runApp(MyApp());
   // runApp(Login());
   // runApp(TestPage());
-  UserData.instance;
+  UserModel.getModel();
 
   print("启动");
 }
@@ -40,6 +40,7 @@ class MyApp extends StatelessWidget {
             "register": (context) => RegisterPage(),
             "login": (context) => LoginPage(),
             "listPage":(context) => List_Page(),
+            "LoginRequestPage":(context) => LoginRequestPage(),
             "main": (context) => mainPage(),
           },
         ),
@@ -88,7 +89,7 @@ class _RouterNavigatorState extends State<RouterNavigator> {
           _item("layout页面", LayoutPage(), 'layout'),
           _item("拍照页面", PhotoApp(), 'photo'),
           _item("登陆", LoginPage(), 'login'),
-          _item("登录网络请求", LoginRequestPage(), 'loginRequest'),
+          _item("登录网络请求", LoginRequestPage(), 'LoginRequestPage'),
           _item("listview页面",List_Page(),'listPage'),
         ],
       ),

netrain_flutter_app/lib/zhangfeng/LoginApi.dart

 import 'Network/HttpManager.dart';
 import 'Network/BaseHttpModel.dart';
 import 'UserModel.dart';
-import 'UserData.dart';
+import 'Network/SaveModel.dart';
 
 /// 所有接口类
 class LoginApi {
@@ -10,7 +10,7 @@ class LoginApi {
     return HttpManager.getInstance().request('auth/oauth/token', parameters: param, onResult: (data,errorMsg){
       BaseHttpModel httpModel = data;
       UserModel userModel = UserModel.fromJson(httpModel.data);
-      UserData.getInstance().saveUserModel(userModel);
+      UserModel.saveModel(userModel);
       if(onResult != null){
         onResult(data, errorMsg);
       }

netrain_flutter_app/lib/zhangfeng/LoginPage.dart

 import 'package:flutter/material.dart';
 import 'package:fluttertoast/fluttertoast.dart';
 import 'package:netrain_flutter_app/zhangfeng/Network/HttpManager.dart';
+import 'package:netrain_flutter_app/zhangfeng/UserModel.dart';
 import 'LoginApi.dart';
-import 'UserData.dart';
 
 class LoginRequestPage extends StatefulWidget {
   final String title = "登录页";
@@ -14,7 +14,7 @@ class LoginRequestPage extends StatefulWidget {
 class _LoginState extends State<LoginRequestPage> {
   // This widget is the root of your application.
   void _loginAction() {
-    if(UserData.instance.userModel != null && UserData.instance.userModel.token != null){
+    if(UserModel.getModel() != null){
       Fluttertoast.showToast(msg:'已经登录');
       return;
     }
@@ -35,7 +35,7 @@ class _LoginState extends State<LoginRequestPage> {
     });
   }
   void _logoutAction() {
-    UserData.instance.removeUserModel();
+    UserModel.removeModel();
     Fluttertoast.showToast(msg:'退出成功');
   }
 

netrain_flutter_app/lib/zhangfeng/UserData.dart → netrain_flutter_app/lib/zhangfeng/Network/SaveModel.dart

 import 'dart:convert';
-
-import 'UserModel.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
-class UserData {
-  UserModel userModel;
-  factory UserData() => getInstance();
-  static UserData get instance => getInstance();
-  static UserData _instance;
-
-  static UserData getInstance() {
-    if (_instance == null) {
-      _instance = new UserData._internal();
-    }
-    return _instance;
-  }
-
-  UserData._internal() {
-    // 初始化
-    getUserModel();
-  }
+class SaveModel {
+  // factory UserData() => getInstance();
+  // static UserData get instance => getInstance();
+  // static UserData _instance;
+  //
+  // static UserData getInstance() {
+  //   if (_instance == null) {
+  //     _instance = new UserData._internal();
+  //   }
+  //   return _instance;
+  // }
+  //
+  // UserData._internal() {
+  //
+  // }
 
-  saveUserModel(UserModel userModel) async {
+  static saveModel(dynamic model,String modelName) async {
     SharedPreferences pref= await SharedPreferences.getInstance();
     //将data转换成json字符串
-    var jsonStr = json.encode(userModel);
-    pref.setString('UserModel',jsonStr);
-    this.userModel = userModel;
+    var jsonStr = json.encode(model);
+    pref.setString(modelName,jsonStr);
   }
 
   // 读取 SharedPreferences
-  getUserModel() async {
+  static Future<Map> getModel(String modelName) async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
-    final jsonStr = prefs.getString('UserModel');
+    final jsonStr = prefs.getString(modelName);
     if(jsonStr != null && jsonStr.length > 0){
       //先将json字符串转json
       Map json = jsonDecode(jsonStr);
-      //将json转model
-      final model = new UserModel.fromJson(json);
-      this.userModel = model;
+      return json;
     }
+    return null;
   }
 
-  removeUserModel() async{
+  static removeModel(String modelName) async{
     SharedPreferences prefs = await SharedPreferences.getInstance();
-    prefs.setString('UserModel',"");
-    this.userModel = null;
+    prefs.setString(modelName,"");
   }
 }
\ No newline at end of file

netrain_flutter_app/lib/zhangfeng/UserModel.dart

 import 'package:json_annotation/json_annotation.dart';
+import 'package:netrain_flutter_app/zhangfeng/Network/SaveModel.dart';
 
 part 'UserModel.g.dart';
 
 @JsonSerializable()
 
 class UserModel{
+  static UserModel sharedModelInstance_;
+
   final token;
   final header;
   final tokenHead;
@@ -13,4 +16,25 @@ class UserModel{
 
   factory UserModel.fromJson(Map<String, dynamic> json) => _$UserModelFromJson(json);
   Map<String, dynamic> toJson() => _$UserModelToJson(this);
+
+  static UserModel getModel(){
+    if(sharedModelInstance_ == null){
+      SaveModel.getModel('UserModel').then((json) => {
+        if(json != null){
+          sharedModelInstance_ = new UserModel.fromJson(json)
+        }
+      });
+    }
+    return sharedModelInstance_;
+  }
+
+  static removeModel() {
+    SaveModel.removeModel('UserModel');
+    sharedModelInstance_ = null;
+  }
+
+  static saveModel(UserModel userModel){
+    sharedModelInstance_ = userModel;
+    SaveModel.saveModel(userModel,'UserModel');
+  }
 }