Flutter第一个应用—踩坑之路

安装

参照官网教程（这里)下载解压，以及设置环境变量即可。

如果你是中国用户（当然了，我们都是），参考这篇文章Using Flutter in China,设置一下中国的镜像。

比如我用的是zsh,那我的设置如下：

export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn

然后使用flutter doctor检查一下环境，我的如下：

• 我的android studio是绿勾勾，是因为我已经安装过Flutter插件了
• 注意上图我红色箭头标注的地方，如果你的没有通过检查,按照doctor的提示输入命令flutter doctor --android-licenses,然后一路Y就行。

创建项目

安装官网的这篇文章使用AS创建项目，但是你会发现，卡在下面这个页面很久

google了很久，得到一个答案，很暴力。

1. 先打开项目文件夹，看是否已经成功创建了文件。（基本都是已经创建了的）
2. 然后强制杀死as
3. 然后重新启动as,打开已存在的项目
4. 但是，按照as的提示Get dependencies时，报Waiting for another flutter command to release the startup lock...错，解决办法是rm flutter/bin/cache/lockfile

编译项目

在编译项目的时候，你会发现，又卡住了，如下图所示：

广大网友们也踩过这些坑，google一通，无外乎如下：

1. 修改android/build.gradle下的仓库地址 ```gr 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'}
   

   }

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'} } }

![](https://cdn.nlark.com/yuque/0/2020/png/170189/1591017317235-c67f0223-f78c-4656-bb93-f4da225add14.png#align=left&display=inline&height=1144&margin=%5Bobject%20Object%5D&originHeight=1144&originWidth=2542&size=0&status=done&style=none&width=2542)

2. 修改flutter安装目录下`./packages/flutter_tools/gradle/flutter.gradle`文件，也是改一下仓库地址
```gr
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:3.5.0'
    }
}

1. Gradle task ‘assembleDebug’ 结束后又报下面的错误 ```

• What went wrong: Execution failed for task ‘:flutter:javaPreCompileDebug’.

  Could not resolve all files for configuration ‘:flutter:debugCompileClasspath’. Could not find io.flutter:flutter_embedding_debug:1.0.0-5b952f286fc070e99cf192775fa5c9dfe858b692. Required by:

     project :flutter
  

  Could not find io.flutter:arm64_v8a_debug:1.0.0-5b952f286fc070e99cf192775fa5c9dfe858b692. Required by:

     project :flutter
  

  Could not find io.flutter:x86_debug:1.0.0-5b952f286fc070e99cf192775fa5c9dfe858b692. Required by:

     project :flutter
  

  Could not find io.flutter:x86_64_debug:1.0.0-5b952f286fc070e99cf192775fa5c9dfe858b692. Required by:

     project :flutter
  

  ```

1. 
   我参考csdn这篇文章，修改了下图这几个文件：

   # 父路径是/opt/flutter/packages/flutter_tools/gradle
   aar_init_script.gradle
   flutter.gradle
   resolve_dependencies.gradle
   

2. 
   

将[https://storage.googleapis.com/download.flutter.io](https://storage.googleapis.com/download.flutter.io)换成[http://download.flutter.io](http://download.flutter.io)（也可以是[https://storage.flutter-io.cn/download.flutter.io](https://storage.flutter-io.cn/download.flutter.io)），修改内容如下图：

至此，终于编译成功了。

Performing hot reload… Syncing files to device Pixel 2… Reloaded 1 of 495 libraries in 584ms.