Flutter Hello World

新建Flutter APP项目

1. 打开Android Stuido -》 选择create flutter app -》填写简单的app信息-》 点击“Finish”。

2. 修改app项目下的android目录下的build.gradle文件，把google() 和 jcenter()这两行去掉，改为一下链接。

maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'https://maven.aliyun.com/repository/jcenter' }
maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }

全部代码：

buildscript {
    repositories {
        /*google()
          jcenter()*/
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public'}
        }
        dependencies {
        classpath 'com.android.tools.build:gradle:3.1.2'
    }
}

allprojects {
    repositories {
        /*google()
          jcenter()*/
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/jcenter' }
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

3. 修改Flutter SDK包下的flutter.gradle文件，把google() 和 jcenter()这两行去掉，改为以下链接，目录为你安装SDK目录，我这边是D:\Sdk\Flutter\flutter\packages\flutter_tools\gradle。

  /*google()
    jcenter()*/
    maven { url 'https://maven.aliyun.com/repository/google' }
    maven { url 'https://maven.aliyun.com/repository/jcenter' }
    maven { url 'http://maven.aliyun.com/nexus/content/groups/public' }

Hello World

import 'package:flutter/material.dart';
//主函数（入口函数）
void main() =>runApp(MyApp());
// 声明MyApp类
class MyApp extends StatelessWidget{
  //重写build方法
  @override
  Widget build(BuildContext context){
    //返回一个Material风格的组件
   return MaterialApp(
      title:'Welcome to Flutteraa',
      home:Scaffold(
        //添加文本
        appBar:AppBar(
          title:Text('Welcome to Flutter'),
        ),
        //添加一个hello world 的文本
        body:Center(
          child:Text('Hello World'),
        ),
      ),
    );
  }
}