2

模型：为类别制作了这个模型。

import 'package:cloud_firestore/cloud_firestore.dart';

class CatagoryModel {

String id;
  String catagoryname;
  Timestamp date;
  bool status;
  String user;

  CatagoryModel(this.id, this.catagoryname, this.date, this.user, this.status);

  CatagoryModel.fromDocumentSnapshot(DocumentSnapshot documentSnapshot) {
    id = documentSnapshot.id;
    catagoryname = documentSnapshot.data()['catagoryname'];
    date = documentSnapshot.data()['date'];
    user = documentSnapshot.data()['user'];
    status = documentSnapshot.data()['status'];
  }
}

服务：此代码处理模型和 Firestore 数据并将其传递给 Getx 控制器。

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:get/get.dart';
import 'package:talhatraders/app/data/catagorymodel.dart';

class Database {
  final FirebaseFirestore _firebase = FirebaseFirestore.instance;

  Future<void> catagoryAdd(String catagoryname,bool status) async {
    try {
      await _firebase.collection('catagorydb').add({
        'date': Timestamp.now(),
        'status': status,
        'catagoryname': catagoryname,
        'user':'user1'
      });
    } catch (e) {
      print(e);
    }
  }

  Future<void> catagoryStatus(CatagoryModel catagorymodel)async{

    try {
      await _firebase.collection('catagorydb').doc(catagorymodel.id).update({'status':!catagorymodel.status});
      
    } catch (e) {
    print(e);
    }

  }

  Future<void> catagoryDelete(CatagoryModel catagorymodel)async{

    try {

      await _firebase.collection('catagorydb').doc(catagorymodel.id).delete();
      
    } catch (e) {
    }
  }

  Stream<List<CatagoryModel>> catagoryStream() {
    return _firebase
        .collection('catagorydb')
        .snapshots()
        .map((QuerySnapshot querysnapshot) {
      List<CatagoryModel> todoData= List();
      querysnapshot.docs.forEach((element) {
        todoData.add(CatagoryModel.fromDocumentSnapshot(element));
      });

      return todoData;
    });
  }
}

Getx 控制器：这里我使用了 obs 字符串，该字符串在从 Dropbox 中选择新值时会发生变化

import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:talhatraders/app/data/catagorymodel.dart';
import 'package:talhatraders/app/modules/catagory/controllers/catagoryservice.dart';

class ProductentryController extends GetxController {
  Rx<List<CatagoryModel>> catagoryList = Rx<List<CatagoryModel>>();

  List<CatagoryModel> get catagories => catagoryList.value;

  var selectedItem = "Select Catagory..".obs;
  void changeSelect(String select) {
    selectedItem.value = select;
    
  }


  @override
  void onInit() {
    catagoryList.bindStream(Database().catagoryStream());
  }
}

GetxViewPaege：在 ViewPage UI 中工作正常，但从下拉列表中选择新值时值没有改变

import 'package:cloud_firestore/cloud_firestore.dart';

import 'package:flutter/material.dart';


import 'package:get/get.dart';
import 'package:flutter/services.dart';

import 'package:talhatraders/app/data/catagorymodel.dart';
import 'package:talhatraders/app/modules/catagory/controllers/catagory_controller.dart';

import 'package:talhatraders/app/modules/productentry/controllers/productentry_controller.dart';



class ProductentryView extends GetView<ProductentryController> {
  ProductentryController productController = Get.put(ProductentryController());




  final FirebaseFirestore _firebase = FirebaseFirestore.instance;
  //Color currentColor =Colors.limeAccent;

 

  String catagory;
  

 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('New Item'),
        actions: [],
      ),
      body: Column(children: [
        GetX<ProductentryController>(
          init: Get.put<ProductentryController>(ProductentryController()),
          builder: (ProductentryController productentryController) {
            return Expanded(
              child: Container(
                child: Padding(
                  padding: const EdgeInsets.only(
                      bottom: 12,top:40, left: 10.0, right: 15.0),
                  child: InputDecorator(
                      decoration: InputDecoration(
                        fillColor: Colors.transparent,
                        hintStyle: Theme.of(context).textTheme.bodyText2,
                        border: OutlineInputBorder(
                          borderRadius: BorderRadius.circular(15),
                          borderSide: BorderSide(
                            width: 10,
                            style: BorderStyle.none,
                          ),
                        ),
                        filled: true,
                        contentPadding: EdgeInsets.all(16),
                      ),
                      child: DropdownButtonHideUnderline(
                        child: DropdownButton(
                            isExpanded: true,
                            isDense:
                                true, // Reduces the dropdowns height by +/- 50%
                            icon: Icon(Icons.keyboard_arrow_down),
                            hint: Text(
                                '${productentryController.selectedItem.toString()}'),
                            value: catagory,
                            items: productentryController.catagories
                                .map((CatagoryModel item) {
                              return DropdownMenuItem(
                                value: item.catagoryname,
                                child: Text(item.catagoryname),
                              );
                            }).toList(),
                            onChanged: (selectedItem) {



                               productentryController.changeSelect(Item);

                              catagory=productController.selectedItem.value;
                            }),
                      )),
                ),
              ),
            );
          },
        ),
      ]),
    );
  }
}
4

2 回答 2

0

这就是我在下拉菜单中使用 GetX 的方式

我正在使用带有 MVC 结构的 GetX，用于列表或响应等的模型，用于在 UI 中显示数据的视图，用于处理业务逻辑的控制器。首先看一下我在这个例子中使用的示例响应。

回复

{
  "users": [
    {
      "user_type_id": "0",
      "user_type": "USER 1"
    },
    {
      "user_type_id": "1",
      "user_type": "USER 2"
    },
    {
      "user_type_id": "2",
      "user_type": "USER 3"
    },
    {
      "user_type_id": "3",
      "user_type": "USER 4"
    }
  ]
}

现在，在您的模型类中。假设-> dropdown_model.dart

这是您列表的模型，将显示在下拉列表中。您可以在 quicktype.io上为您的回复创建模型

import 'dart:convert';

DropdownModel dropdownModelFromJson(String str) => DropdownModel.fromJson(json.decode(str));

String dropdownModelToJson(DropdownModel data) => json.encode(data.toJson());

class DropdownModel {
  DropdownModel({
    this.users,
  });

  List<User> users;

  factory DropdownModel.fromJson(Map<String, dynamic> json) => DropdownModel(
    users: List<User>.from(json["users"].map((x) => User.fromJson(x))),
  );

  Map<String, dynamic> toJson() => {
    "users": List<dynamic>.from(users.map((x) => x.toJson())),
  };
}

class User {
  User({
    this.userTypeId,
    this.userType,
  });

  String userTypeId;
  String userType;

  factory User.fromJson(Map<String, dynamic> json) => User(
    userTypeId: json["user_type_id"],
    userType: json["user_type"],
  );

  Map<String, dynamic> toJson() => {
    "user_type_id": userTypeId,
    "user_type": userType,
  };
}

现在，在您的 Controller 类中。假设-> register_controller.dart

//Make sure to import required packages
class RegisterController extends GetxController{

  //Declaration and initializations
  DropdownModel model;
  Rx<List<User>> userTypeListM = Rx<List<User>>();
  Rx<User>selectedUserType = Rx<User>();
  Rx<String>userTypeId = Rx<String>();
  
  //this is used, just to avoid any null error until list is fetched
  var toggle = false.obs;

  //This is a sample api call, fetch your data/list and assign list to RxList, 
  //Your API Call goes right in this method
  getList() async {
    String data = await rootBundle.loadString('assets/user_type.json');
    model = dropdownModelFromJson(data);
    //if in case userTypeListM.value doesn't work then try userTypeListM.assignAll(model.users) 
    userTypeListM.value = model.users;
    toggle.value = true;
  }

//Call getList() in onInit() method
@override
  void onInit() {
    // TODO: implement onInit
    super.onInit();
    getList();
  }


onSelectionChange(User value){
    
    selectedUserType.value = value;
    userTypeId.value = value.userTypeId;
   
  }

}

现在，在您的 View 类中。假设-> register_view.dart

//Make sure to import required packages
class RegisterPage extends StatelessWidget{

final registerController = Get.put(RegisterController());

@override
  Widget build(BuildContext context) {
    return Scaffold(
       body:Center(
         child:Row(
             children:[
                Expanded(
                   flex:1,
                   child: Container(
                      //color: Colors.white,
                      margin: EdgeInsets.only(left: 15,right: 15,top: 16,bottom: 0),
                      padding: EdgeInsets.symmetric(vertical: 5, horizontal: 8),
                      decoration: BoxDecoration(
                         borderRadius: BorderRadius.circular(30),
                         color: Colors.white,
                         boxShadow: [
                            BoxShadow(
                               color: CupertinoColors.lightBackgroundGray,
                               spreadRadius: 5,
                               blurRadius: 25,
                               offset: Offset(5,5),
                            ),
                         ]
                      ),
                      child: Column(
                         /* crossAxisAlignment: CrossAxisAlignment.center,
                         mainAxisAlignment: MainAxisAlignment.center,*/
                         children: <Widget>[
                            Obx(()=> registerController.toggle.value
                                 ? DropdownButton(
                                      value: registerController.selectedUserType!=null ? registerController.selectedUserType.value: null,
                                      items: registerController.userTypeListM.value
                                      .map<DropdownMenuItem<User>>((User value) {
                                      return DropdownMenuItem<User>(
                                        value: value,
                                        child: Text(value.userType.toString()),
                                      );
                                    }).toList(),
                                    onChanged: (User value){
                                      registerController.selectedUserType.value = value;
                                      registerController.userTypeId.value = value.userTypeId;
                                      
                                      registerController.update();
                                    },
                                    underline: Container(color: Colors.transparent,),
                                    hint: Text("Select value from dropdown"),
                                    isExpanded: true,
                                  )
                                      : Container()
                                  )
                                ],
                              )
                          ),
                       ),
                    ]
                 ),
             )
        );
    }
}

而已！。它应该与下拉列表中的任何自定义模型一起使用。

于 2021-04-06T15:12:03.023 回答
0

像这样创建一个 Dropdown Picker 类并在需要的地方使用它

class DropdownPickerGetX extends StatelessWidget {
  DropdownPickerGetX(
      {this.menuOptions, this.selectedOption, this.onChanged});

  final List<dynamic> menuOptions;
  final String selectedOption;
  final void Function(String) onChanged;

  @override
  Widget build(BuildContext context) {
    //if (Platform.isIOS) {}
    return DropdownButton<String>(
        items: menuOptions
            .map((data) => DropdownMenuItem<String>(
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.start,
                    children: <Widget>[
                      Icon(data.icon),
                      SizedBox(width: 10),
                      Text(
                        data.value,
                      ),
                    ],
                  ),
                  value: data.key,
                ))
            .toList(),
        value: selectedOption,
        onChanged: onChanged);
  }
}
于 2021-04-06T06:43:34.077 回答