我是 dart 新手,在构建 Flutter 应用程序时遇到问题。
我有一个 firestore 数据库作为后端,我从那里获取数据。
当我想使用 == 比较器将名为 status 的部分数据与文本“CREATED”进行比较时,dart 将返回 false。
有人可以解释为什么以及如何正确检查它吗?
rideObject 是一个地图
更新:
这是包含条件的函数:
Widget _getPage() {
if (rideObject == null) {
return OrderRidePage(
address: address,
ridesReference: reference,
setRideReference: this._setRideReference);
} else {
print(rideObject['status']);
if (rideObject['status'] == "CREATED") {
return LoadingPage(
removeRideReference: this._removeRideReference,
rideReference: rideReference);
} else {
return RidePage(
address: address,
ridesReference: reference,
setRideReference: _setRideReference);
}
}
}
Run Code Online (Sandbox Code Playgroud)
print语句返回输出:
我/颤振(15469):已创建
这里可以看到rideObject的结构
有趣的是,rideObject["status"] 是 String 类型,如控制台中所示:
rideObject["status"] is String
true
"CREATED" is String
true …Run Code Online (Sandbox Code Playgroud) 我试图反序列化我已经通过JSON格式POST但有一些问题的数据.
错误消息是:
SerializationException:期望状态'Element'..遇到名为'',namespace''的'Text'.System.Runtime.Serialization.XmlObjectSerializerReadContext.HandleMemberNotFound(XmlReaderDelegator的XMLReader,ExtensionDataObject extensionData,INT memberIndex)
发生序列化的控制器:
public String RequestToken(string userData)
{
Contract.Ensures(Contract.Result<string>() != null);
UserModel deserializedUser = new UserModel();
MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(userData));
ms.Position = 0;
DataContractJsonSerializer ser = new DataContractJsonSerializer(deserializedUser.GetType());
deserializedUser = ser.ReadObject(ms) as UserModel;
}
Run Code Online (Sandbox Code Playgroud)
用作合同的UserModel:
using System;
using System.Runtime.Serialization;
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
namespace WishareIntegrationApi.Entities
{
[DataContract]
public class UserModel
{
[BsonId]
[BsonRepresentation(BsonType.String)]
[DataMember]
public ObjectId _id { get; set; }
[DataMember]
public string displayName { get; set; }
[DataMember]
public string photoURL { get; set; …Run Code Online (Sandbox Code Playgroud) 我正在尝试做一个http://spring.io/guides/gs/rest-service/教程,我在教程中做了类似的事情.
当我尝试使用gradle构建时,gradle.build来自教程gradle构建失败,因为缺少
springBoot {
mainClass = "main.java.hello.Application"
}
Run Code Online (Sandbox Code Playgroud)
我确实添加了它,现在编译正确地开始和结束,但是一旦我想要做
java -jar build/libs/gs-rest-service-0.1.0.jar
它抛出一个错误 
我不知道该怎么做.有帮助吗?
我需要帮助。我创建了视图,在其中为一种类型的对象创建多个表单。现在我想保存表单,所有这些都只需一个按钮,然后将这些对象保存到数据库中。
这是控制器:
/**
* @Route("/project/{project_id}/string/{id}/edit/", name="StringEdit")
* @Template()
*/
public function editAction($project_id, $id, Request $request)
{
$string = $this->getDoctrine()->getRepository('DomestosTranslatingBundle:String')->find($id);
$translations = $this->getDoctrine()->getRepository('DomestosTranslatingBundle:Translation')->findByString($string);
//$form = $this->createForm(new TranslationType(), $translation);
//$form->handleRequest($request);
$forms = array();
foreach($translations as $translation){
$form = $this->createForm(new TranslationType, $translation);
$form = $form->createView();
$forms[] = $form;
}
return $this->render('DomestosTranslatingBundle:String:edit.html.twig', array(
'forms' => $forms,
'string' => $string,
));
}
Run Code Online (Sandbox Code Playgroud)
和观点:
{% extends "::base.html.twig" %}
{% block title %}Edit translations{% endblock %}
{% block body %}
Code: {{string.code}}
<p>
<table>
{% for keylang,lang …Run Code Online (Sandbox Code Playgroud) 我需要编写一个只匹配这种格式的正则表达式
+420 000 000 000
+420000000000
420 000 000 000
420000000000
Run Code Online (Sandbox Code Playgroud)
它不能匹配字符串任何部分中的任何az字符,只是数字,空格和开头的"+".
我有一个控制器
var videoApp = angular.module('videoApp', ['videoAppFilters', 'ui.unique', 'angularUtils.directives.dirPagination']);
videoApp.controller('VideoCtrl', function ($scope, $http, $filter, cacheLoader, $rootScope) {
$scope.setPageSize = function (pageSize) {
$scope.pageSize = pageSize;
return $scope.pageSize;
};
$scope.addFavorite = function (data, key) {
localStorage.setItem(key, data);
$scope.videos = $filter('articleFilter')(data, $scope.allData);
return alert(key + " "+ data + " was added to your favorite list.");
};
$scope.addSelectedClass = function (event) {
if($(event.target).hasClass("selected") == true)
{
$(event.target).removeClass("selected");
} else {
$(".selected").removeClass("selected");
$(event.target).addClass("selected");
}
};
$scope.filterArticles = function (category) {
$scope.videos = $filter('articleFilter')(category, $scope.allData); …Run Code Online (Sandbox Code Playgroud)