Flutter第一個應用--踩坑之路

安裝

參照官網教程（這裡)下載解壓，以及設置環境變數即可。

如果你是中國用戶（當然了，我們都是），參考這篇文章Using Flutter in China,設置一下中國的鏡像。

比如我用的是zsh,那我的設置如下：

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

然後使用flutter doctor檢查一下環境，我的如下：

• 我的android studio是綠勾勾，是因為我已經安裝過Flutter插件了
• 註意上圖我紅色箭頭標註的地方，如果你的沒有通過檢查,按照doctor的提示輸入命令flutter doctor --android-licenses,然後一路Y就行。

創建項目

安裝官網的這篇文章使用AS創建項目，但是你會發現，卡在下麵這個頁面很久

google了很久，得到一個答案，很暴力。

1. 先打開項目文件夾，看是否已經成功創建了文件。（基本都是已經創建了的）
2. 然後強制殺死as
3. 然後重新啟動as,打開已存在的項目
4. 但是，按照as的提示Get dependencies時，報Waiting for another flutter command to release the startup lock...錯，解決辦法是rm flutter/bin/cache/lockfile

編譯項目

在編譯項目的時候，你會發現，又卡住了，如下圖所示：

廣大網友們也踩過這些坑，google一通，無外乎如下：

1. 修改android/build.gradle下的倉庫地址

   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'}
       }
   }
   

2. 修改flutter安裝目錄下./packages/flutter_tools/gradle/flutter.gradle文件，也是改一下倉庫地址

   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'
       }
   }
   

   ---

   Gradle task 'assembleDebug' 結束後又報下麵的錯誤

   * 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
   

   我參考csdn這篇文章，修改了下圖這幾個文件：

   # 父路徑是/opt/flutter/packages/flutter_tools/gradle
   aar_init_script.gradle
   flutter.gradle
   resolve_dependencies.gradle
   

   

將https://storage.googleapis.com/download.flutter.io換成http://download.flutter.io（也可以是https://storage.flutter-io.cn/download.flutter.io），修改內容如下圖：

至此，終於編譯成功了。

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