Could not resolve all files for configuration ':classpath'.

Could not resolve com.android.tools.build:gradle:3.0.1. Required by: project : > Could not resolve com.android.tools.build:gradle:3.0.1. > Could not get resource ' maven.google.com/com/android… '. > Could not GET ' maven.google.com/com/android… '. > Connect to maven.google.com:443 [maven.google.com/142.251.43.14] failed: Connection timed out: connect

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

修改Project的build.gradle（注意：不是App的build.gradle），两处加上google()，如下所示：

buildscript {
    repositories {
        maven {
            url "https://maven.google.com"
        jcenter()
        google()
    dependencies {
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
        classpath 'com.android.tools.build:gradle:3.0.1'
allprojects {
    repositories {
        maven {
            url "https://maven.google.com"
        jcenter()
        google()
    //This replaces project.properties w.r.t. build settings
    project.ext {
      defaultBuildToolsVersion="27.0.1" //String
      defaultMinSdkVersion=19 //Integer - Minimum requirement is Android 4.4
      defaultTargetSdkVersion=27 //Integer - We ALWAYS target the latest by default
      defaultCompileSdkVersion=27 //Integer - We ALWAYS compile with the latest by default
复制代码