widget

问题 I was trying to send an email and save the user input data to the firebase from the flutter application. My code does: I have created the application which is capable to send email but I have got stuck to save those text fields data in the firebase. I have implemented the cloud firestore in the code but I am getting quite a few errors. My code: import 'package:flutter/material.dart'; import 'dart:async'; import 'package:flutter_email_sender/flutter_email_sender.dart'; import 'package:cloud

问题 In the example below when I push new MaterialPageRoute it is created on the same level as Home widget in the Flutter widget tree. I would like to have it as a child of widget Home, so Home would be a parent of Child widget. Here is a full code: import 'package:flutter/material.dart'; void main() { runApp(MaterialApp( home: Home(), )); } class Home extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( body: Column( children: <Widget>[ Center( child: Text(

问题 How can i create Header project in react and want to share the same to other projects without npm? Is there any way I can share script and selector like <Header></Header> and they can use the same? I have tried so many things but cann't able to share with other projects. 回答1: Maybe you are talking about reusing Header component in some other project. I suggest you to take a look at Storybook . You can simply add that same component inside the new application and then use it there. 来源： https:/

问题 I'm struggling a bit with the text widget in the tkinter module. I have added tags that I try to bind a function to. Regardless of how I type it, it happens one of two things. Either I can click in the text widget but the only function popping up is for the last item regardless of where i click. Number two that happens is that it just spews out all functions automatically. Did an edit on the original post and removed the coding i've typed. Have made the same function calls here as I had in

问题 Hey so my code refers to this here : Multiple dependent widgets (dropdown menu) on Jupyter notebook from ipywidgets import interact, Dropdown enfrom ipywidgets import interact, Dropdown geo = {'USA':['CHI','NYC'],'Russia':['MOW','LED']} geo2={'CHI':['1','2'],'NYC':['3','4'],'MOW':['5','6'],'LED':['7','8']} countryW = Dropdown(options = geo.keys()) cityW = Dropdown(options = geo[countryW.value]) # options = geo[countryW.value] is to remove inital error but not that necessary. districtW =

问题 I am trying to use the drawer to navigate (yield) to the same class (CategoryListPage) with different parameters it doesnt seem to update the widget page. but if I go HomePage then yield CategoryListPage(), it works. What can I do to navigate to the same class, is there a way to refresh the content ? here is my code: class NavigationBloc extends Bloc<NavigationEvents, NavigationStates> { @override NavigationStates get initialState => HomePage(); @override Stream<NavigationStates>

问题 I want to show weather on my website. I looked into all the weather widgets I could find online, none of them looked as cool as the one I see on google ( when i search weather for my city ) and I could not find any documentation on how to embed it in my website. I'd like to know if there is any way I can plugin the exact google widget in my website. (the one I see when I search for weather ) There is another option of calling the service and building the whole widget, I looked at some of the

问题 I was following the example on how to handle multiple dependent widgets on jupyter notebooks from here: Dynamically changing dropdowns in IPython notebook widgets and Spyre In that example the code solution was the following: from IPython.html import widgets from IPython.display import display geo={'USA':['CHI','NYC'],'Russia':['MOW','LED']} def print_city(city): print city def select_city(country): cityW.options = geo[country] scW = widgets.Dropdown(options=geo.keys()) init = scW.value cityW

问题 I just need some idea on how flutter stateful widgets build their stateful children when setState() is invoked. Please look at the code below. class MyStatefulWidget extends StatefulWidget { MyStatefulWidget({Key key}) : super(key: key); @override _MyStatefulWidgetState createState() => _MyStatefulWidgetState(); } class _MyStatefulWidgetState extends State<MyStatefulWidget> { Widget build(BuildContext context) { print("Parent build method invoked"); return Scaffold( body: Center( child:

问题 I am trying to toggle the color of a raised button. Initially the button should be blue and when it is pressed it turns to grey. Right now I have a bool value called pressAttention and it is set to false. I am using this to initially set this the false. When the button is pressed it toggles the pressAttention bool, but it seems that the widget is never updated again. new RaisedButton( child: new Text("Attention"), textColor: Colors.white, shape: new RoundedRectangleBorder(borderRadius: new