小编Azi*_*ark的帖子

我是 Flutter 新手，刚刚学会了如何在 Dart 中使用隔离。当我尝试通过隔离访问共享首选项时，它会抛出以下给出的错误。当我尝试访问 Firebase 分析和远程配置时，也会出现此错误。如何解决此问题并访问隔离内的 SharedPreference、FirebaseRemote 配置、FirebaseFirestore？

[ERROR:flutter/runtime/dart_isolate.cc(882)] Unhandled exception:
E/flutter (23694): ServicesBinding.defaultBinaryMessenger was accessed before the binding was initialized.
E/flutter (23694): If you're running an application and need to access the binary messenger before `runApp()` has been called (for example, during plugin initialization), then you need to explicitly call the `WidgetsFlutterBinding.ensureInitialized()` first.
E/flutter (23694): If you're running a test, you can call the `TestWidgetsFlutterBinding.ensureInitialized()` as the first line in your test's `main()` method to initialize the binding. …

我想从输入'x + y'中删除"+"符号,其中x和y是一个字符串(单个数字)并打印结果.

例如,我输入5 + 7它应该显示57

这是代码:

opr = input("Enter string").strip("+")
print(opr)

此代码未删除"+"符号请帮忙!

如何为单个视图在本地导入样式表。

我有两个视图/home和/blog以下文件目录：

src
?  
????components       
      ?
      ????Home
      ?     Home.js
      ?     Home.css
      ????Blog
            Blog.js
            Blog.css

我有一个单独的 css 文件home.css仅用于主页视图，但该样式也应用于博客视图。

我希望home.css文件仅适用于home.js视图。

主页.css

.text1 {
   font-size: 1em !important;
   font-family: "Noto Sans", sans-serif !important;
   color: red;
 }

主页.js

import React, { Component } from "react";
import "./home.css";

class Home extends Component {
  render() {
    return (
      <div className="text1" style={{ overflow: "Hidden" }}>
        <h1>This must be red.</h1>
        <a href="/blog">Go to Blog</a>
      </div> …