Flutter项目启动一直卡在Running Gradle task ‘assembleDebug‘问题解决

问题描述：按照flutter官网步骤安装Flutter SDK、Android studio等，在创建第一个flutter项目后run的过程一直是Running Gradle task ‘assembleDebug’…
解决方法：
1、修改android\build.gradle文件

buildscript {
     repositories {
         //修改的地方
        //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:3.2.1'
     }
 }

allprojects {
     repositories {
         //修改的地方
        //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
 }

2、修改Flutter的配置文件, 该文件在Flutter安装目录/packages/flutter_tools/gradle/flutter.gradle

buildscript {
     repositories {
         //修改的地方
        //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'
     }
 }

按照网上的一些说法，此时重新run项目即可解决，但我的仍然报错，继续修改配置文件：
3、继续修改 Flutter安装目录/packages/flutter_tools/gradle/flutter.gradle文件

private static final String MAVEN_REPO = "https://storage.googleapis.com/download.flutter.io";

修改为

private static final String MAVEN_REPO = "https://storage.flutter-io.cn/download.flutter.io";

（也有的修改为：

private static final String MAVEN_REPO      = "https://mirrors.tuna.tsinghua.edu.cn/flutter/download.flutter.io";

或

private static final String MAVEN_REPO      = "http://download.flutter.io"; 

供参考
）

4、修改文件Flutter安装目录/packages/flutter_tools/gradle/resolve_dependencies.gradle
第20行的maven为：

	maven {
        url "http://download.flutter.io"
    }

此时重新run项目，成功运行。

（另外网上有另一种解决方法，没有尝试过）

仅此记录，仅供参考
End