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firebase - Flutter:无法使用静态访问访问实例成员 'signInWithGoogle'。 (static_access_to_instance_member 在)

我尝试为我的Flutter项目进行lint,我有一个用于登录和注销谷歌帐户的类API,Linter更喜欢在这些方法之前删除静态(使用Google登录并注销)。我无法在View中调用这些函数。这是我的代码:API.dartclassFBApi{FBApi(this.firebaseUser);...FuturesignInWithGoogle()async{finalGoogleSignInAccountgoogleUser=await_googleSignIn.signIn();finalGoogleSignInAuthenticationgoogleAuth=awaitgoogleU

dart - 尝试调用 : ancestorStateOfType(Instance of 'TypeMatcher<NavigatorState>'

我正在尝试在ListView中点击行项目来调用新页面,我对flutter很陌生classMyAppextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){returnMaterialApp(title:"MyFirstFlutterApp",home:newHome());}}classHomeextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){//TODO:implementbuildreturnnewScaffold(appBar:

dart - 尝试调用 : ancestorStateOfType(Instance of 'TypeMatcher<NavigatorState>'

我正在尝试在ListView中点击行项目来调用新页面,我对flutter很陌生classMyAppextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){returnMaterialApp(title:"MyFirstFlutterApp",home:newHome());}}classHomeextendsStatelessWidget{@overrideWidgetbuild(BuildContextcontext){//TODO:implementbuildreturnnewScaffold(appBar:

class - 错误 "Can' t access this in a field initializer 是什么意思”?

我想在flutter中创建一个显示警告框的类,它可以将标题和内容作为输入来显示错误框。但是当我使用它来访问AlertDialog()中同一类的变量时,调试控制台说“无法在字段初始值设定项中访问它”。import'package:flutter/material.dart';voidmain()=>runApp(MaterialApp(home:Alert("SayHy","Hy"),));classAlertextendsStatelessWidget{finalStringtitlea;finalStringcontexta;Alert(this.titlea,this.contex

class - 错误 "Can' t access this in a field initializer 是什么意思”?

我想在flutter中创建一个显示警告框的类,它可以将标题和内容作为输入来显示错误框。但是当我使用它来访问AlertDialog()中同一类的变量时,调试控制台说“无法在字段初始值设定项中访问它”。import'package:flutter/material.dart';voidmain()=>runApp(MaterialApp(home:Alert("SayHy","Hy"),));classAlertextendsStatelessWidget{finalStringtitlea;finalStringcontexta;Alert(this.titlea,this.contex

class org.apache.kafka.common.serialization.StringSerializer is not an instance of org.apache.kafka.

问题当我们运行一个程序报错classorg.apache.kafka.common.serialization.StringSerializerisnotaninstanceoforg.apache.kafka.common.serialization.Deserializer原因classorg.apache.kafka.common.serialization.StringSerializer不是org.apache.kafka.common.serialization.Deserializer的实例从而无法创建消费者Failedtoconstructkafkaconsumer解决将Str

Unknown column ‘xxx‘ in ‘field list‘

MySQL数据库插入数据时,出现Unknowncolumn'XXX'in'fieldlist' 问题('XXX'表示任意字符)。例如下面:--删除表DROPTABLEIFEXISTStbl_log;createtabletbl_log( idintprimarykeyauto_increment,infovarchar(255),createDatedatetime)然后向其中插入一行数据:publicinterfaceLogDao{@Insert("insertintotbl_log(info,createDate)values(#{info},now())")voidlog(Stringi

dart - flutter scoped_model : Is it possible to pass data to a field of a model class?

是否可以将数据传递到模型类的字段?从onPressed方法说起。它不接受带有参数'onPressed:model.setNumber(25)'的onPressed函数,或者有什么方法可以做到这一点?Redux是否与这种类型的数据传递有关?我提供了以下代码:import'package:flutter/material.dart';import'package:scoped_model/scoped_model.dart';voidmain(){runApp(newMyApp());}classMyAppextendsStatelessWidget{@overrideWidgetbuil

dart - flutter scoped_model : Is it possible to pass data to a field of a model class?

是否可以将数据传递到模型类的字段?从onPressed方法说起。它不接受带有参数'onPressed:model.setNumber(25)'的onPressed函数,或者有什么方法可以做到这一点?Redux是否与这种类型的数据传递有关?我提供了以下代码:import'package:flutter/material.dart';import'package:scoped_model/scoped_model.dart';voidmain(){runApp(newMyApp());}classMyAppextendsStatelessWidget{@overrideWidgetbuil

http - 为什么 FutureBuilder snapshot.data 返回 "Instance of Post"而不是 json?

我期待一个JSON数据对象,但却得到了Instanceof'Post'我是Flutter的新手,正在尝试使用http.dart包通过发布请求访问API。我正在使用一个异步future和一个future建筑来用返回的数据填充一个小部件(按照这里的flutter示例:https://flutter.io/docs/cookbook/networking/fetch-data)。FuturefetchPost()async{Stringurl="https://example.com";finalresponse=awaithttp.post(url,headers:{HttpHeaders