Question

我遇到以下错误，但找不到原因。

那里发生了什么

有2个下拉按钮。第二个按钮取决于第一个按钮的值。然后显示与第二个按钮的结果值相关的表格。

但是我得到了屏幕截图中显示的错误）。我找不到问题。

我在下面附上了代码。

import 'package:carousel_pro/carousel_pro.dart';
import 'package:carousel_slider/carousel_slider.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:multi_image_picker/multi_image_picker.dart';

import 'categories/vehicles/car.dart';
import 'categories/vehicles/van.dart';

import 'services/utils.dart';



class AdAdvertisement extends StatefulWidget {
  final GlobalKey<ScaffoldState> globalKey;
  const AdAdvertisement({Key key, this.globalKey}) : super(key: key);
  @override
  _AdAdvertisementState createState() => _AdAdvertisementState();
}

class _AdAdvertisementState extends State<AdAdvertisement> {
  var selectedCurrency,selectedSub;
  var  selectedCurrency2, selectedType;
  var value;
  final databaseReference = Firestore.instance;
  String now = new DateTime.now().toString();
  List<Asset> images = List<Asset>();
  //List<NetworkImage> _listOfImages = <NetworkImage>[];
  List<String> imageUrls = <String>[];
  //List<String> imageLocalLink = <String>[];
  String _error = 'No Error Dectected';
  bool isUploading = false;
  bool carosal = false;


  final _formKeyCar = GlobalKey<FormState>();
  final _formKeyVan = GlobalKey<FormState>();

  var category_names = Firestore.instance.collection("category_names").snapshots();
  
  void ValueChanged(var currencyValue){
    setState(() {
          selectedCurrency =currencyValue;
        });
  }

  void ValueSubchange(var subcategory){
    setState(() {
          selectedSub=subcategory;
        });
  }

  void createRecord() async {
    await databaseReference.collection("Advertisements")
        .document(now)
        .setData({
          'title': 'Mastering Flutter',
          'description': 'Programming Guide for Dart'
        });

    
  }

  Widget _widgetForm() {
    switch (selectedSub) {
      case "car":
        return carForm();
        break;
      case "van":
        build(context){
          return vanForm();
        };
        //return _vanForm();
        break;
    }
  }
  //
  
  //

  Future<void> loadAssets() async {
    List<Asset> resultList = List<Asset>();
    String error = 'No Error Dectected';
    try {
      resultList = await MultiImagePicker.pickImages(
        maxImages: 10,
        enableCamera: true,
        selectedAssets: images,
        cupertinoOptions: CupertinoOptions(takePhotoIcon: "chat"),
        materialOptions: MaterialOptions(
          actionBarColor: "#abcdef",
          actionBarTitle: "Upload Image",
          allViewTitle: "All Photos",
          useDetailsView: false,
          selectCircleStrokeColor: "#000000",
        ),
      );
      print(resultList.length);
      print((await resultList[0].getThumbByteData(122, 100)));
      print((await resultList[0].getByteData()));
      print((await resultList[0].metadata));

    } on Exception catch (e) {
      error = e.toString();
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;
    setState(() {
      images = resultList;
      carosal = true;
      print('<<<<<<<<<<<<<<<<<<<');
      print(images);
      
      
      //_listOfImages = imageUrls.cast<NetworkImage>();
      _error = error;
    });
  }
  Widget _imageShow(){
    if(carosal==true){
      return CarouselSlider(
        items: images
        .map((e) => AssetThumb(asset:e, width: 300, height: 300,))
        .toList(),
        options: CarouselOptions(
          height: 400,
          aspectRatio: 16 /9 ,
          viewportFraction: 0.8,
          initialPage: 0,
          enableInfiniteScroll: true,
          reverse: false,
          autoPlay: true,
          autoPlayInterval: Duration(seconds: 3),
          autoPlayAnimationDuration: Duration(milliseconds: 800),
          autoPlayCurve: Curves.fastOutSlowIn,
          enlargeCenterPage: true,
          scrollDirection: Axis.horizontal,

        ),  
      );
    }
    else{
      return Text('not yet selected');
    }
  }

  void uploadImages(){
  
    for ( var imageFile in images) {
      postImage(imageFile).then((downloadUrl) {
        imageUrls.add(downloadUrl.toString());
        if(imageUrls.length==images.length){
          String documnetID = DateTime.now().millisecondsSinceEpoch.toString();
          Firestore.instance.collection('images').document(documnetID).setData({
            'urls':imageUrls
          }).then((_){
            SnackBar snackbar = SnackBar(content: Text('Uploaded Successfully'));
            //widget.globalKey.currentState.showSnackBar(snackbar);
            setState(() {
              images = [];
              imageUrls = [];
              carosal =false;
            });
          });
        }
      }).catchError((err) {
        print(err);
      });
    }

  }

  Future<dynamic> postImage(Asset imageFile) async {
    String fileName = DateTime.now().millisecondsSinceEpoch.toString();
    StorageReference reference = FirebaseStorage.instance.ref().child(fileName);
    StorageUploadTask uploadTask = reference.putData((await imageFile.getByteData()).buffer.asUint8List());
    StorageTaskSnapshot storageTaskSnapshot = await uploadTask.onComplete;
    print(storageTaskSnapshot.ref.getDownloadURL());
    return storageTaskSnapshot.ref.getDownloadURL();
  }

  Widget _carForm() {
    return Card(
      child: Form(
        
        //key: _formKeyVan,
        child: Column(children: <Widget>[
          // Add TextFormFields and RaisedButton here.
          //buildGridView(),
          TextFormField(
             
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Brand';
            //  }
            //  //return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter your Car Brand',
              labelText: 'Brand',
              prefixIcon: Icon(Icons.add_circle) 
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Model';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter your Car Model',
              labelText: 'Car Model',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Model Year';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Car Model year',
              labelText: 'Model Year',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Mileage';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Mileage',
              labelText: 'Mileage ',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Enter Transmission type';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Transmission type',
              labelText: 'Transmission ',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Fueltype';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Fuel type',
              labelText: 'Fueltype ',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Engine capaciy';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Engine capacity',
              labelText: 'Engine capacity(cc) ',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please enter Description';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Description here',
              labelText: 'Description ',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          TextFormField(
            //validator: (value) {
            //  if (value.isEmpty) {
            //    return 'Please Price';
            //  }
            //  return null;
            //},
            decoration: const InputDecoration(
              hintText: 'Enter Price',
              labelText: 'Price',
              prefixIcon: Icon(Icons.add_circle)
            ),
          ),
          SizedBox(height: 20.0),
          RaisedButton(
            child: new Text("add Image"),
            onPressed: loadAssets,
          ),
          SizedBox(height: 10.0,),
          _imageShow(),
          
          RaisedButton(
              child: new Text("upload"),
              onPressed: (){
                if(images.length==0){
                  showDialog(context: context,builder: (_){
                    return AlertDialog(
                      backgroundColor: Theme.of(context).backgroundColor,
                     content: Text("No image selected",style: TextStyle(color: Colors.white)),
                     actions: <Widget>[
                      RaisedButton(
                        onPressed: (){
                          Navigator.pop(context);
                        },
                        child: Center(child: Text("Ok",style: TextStyle(color: Colors.white),)),
                      )
                      
                     ],
                    );
                  });
                }
                else{
                  SnackBar snackbar = SnackBar(content: Text('Please wait, we are uploading'));
                  //widget.globalKey.currentState.showSnackBar(snackbar);
                  uploadImages();
                }
              },
          ),
          SizedBox(height: 20.0),
          RaisedButton(
              color: Color(0xff11b719),
              textColor: Colors.white,
              child: Padding(
              padding: EdgeInsets.all(10.0),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: <Widget>[
                  Text("Submit", style: TextStyle(fontSize: 24.0)),
                ],
              )),
              onPressed: () {
                  createRecord();
              },
              shape: new RoundedRectangleBorder(
                  borderRadius: new BorderRadius.circular(30.0)
                )
              ),
              
              
        ]
        )
        )
    );
  }
  List<DropdownMenuItem> currencyItems2 = [];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Container(
            alignment: Alignment.center,
            child: Text('Advertisement'),
          ),
        ),
        body: ListView(
          children: <Widget>[
            Text('Select category here'),
            Text('Select category here'),
            SizedBox(height: 40.0),
            StreamBuilder<QuerySnapshot>(
              stream: category_names,
              builder: (context, snapshot) {
                if (!snapshot.hasData)
                  return Text("Loading.....");
                else {
                  List<DropdownMenuItem> currencyItems = [];
                  for (int i = 0; i < snapshot.data.documents.length; i++) {
                    DocumentSnapshot snap = snapshot.data.documents[i];
                    currencyItems.add(
                      DropdownMenuItem(
                        child: Text(
                          snap.documentID,
                          style: TextStyle(color: Color(0xff11b719)),
                        ),
                        value: "${snap.documentID}",
                      ),
                    );
                  }
                  return Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      SizedBox(width: 20.0),
                      DropdownButton(
                        items: currencyItems,
                        onChanged: (currencyValue) {
                          setState(() {
                            selectedCurrency = currencyValue;
                            //disabledropdown = true;
                          });
                          for (int i = 0;
                              i < snapshot.data.documents.length;
                              i++) {
                            DocumentSnapshot snap = snapshot.data.documents[i];
                            if (snap.documentID == selectedCurrency) {
                              for (int j = 0; j < snap.data.length; j++) {
                                currencyItems2.add(
                                  DropdownMenuItem(
                                    child: Text(
                                      snap.data['${j + 1}'].toString(),
                                      style:
                                          TextStyle(color: Color(0xff11b719)),
                                    ),
                                    value: snap.data['${j + 1}'].toString(),
                                  ),
                                );
                              }
                            }
                          }
                          final snackBar = SnackBar(
                            content: Text(
                              'Selected Currency value is $currencyValue',
                              style: TextStyle(color: Color(0xff11b719)),
                            ),
                          );
                          Scaffold.of(context).showSnackBar(snackBar);
                        },
                        value: selectedCurrency,
                        isExpanded: false,
                        hint: new Text(
                          "Choose Category Type",
                          style: TextStyle(color: Color(0xff11b719)),
                        ),
                      ),
                      DropdownButton(
                        items: currencyItems2,
                        onChanged: (currencyValue) {
                          final snackBar = SnackBar(
                            content: Text(
                              'Selected Currency value is $currencyValue',
                              style: TextStyle(color: Color(0xff11b719)),
                            ),
                          );
                          Scaffold.of(context).showSnackBar(snackBar);
                          setState(() {
                            selectedCurrency2 = currencyValue;
                          });
                        },
                      ),
                    ],
                  );
                }
              }),
          _widgetForm(),
          Card(
            child: InkWell(
              splashColor: Colors.blue.withAlpha(30),
              onTap: () {
                print('Card tapped.');
              },
              child: Container(
                width: 300,
                height: 100,
                child: Text('A card that can be tapped'),
              ),
            ),
          ),
                  
              _widgetForm(),
            
              
          ],
        ),
    );
  }
}

方法和吸气剂称为零抖动

0 个答案: