title: android studio Could not resolve com.android.support:appcompat-v7:26.1.0
body: <p>erro details:</p>
  
  <p>Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve com.android.support:appcompat-v7:26.1.0.</p>
  
  <p>Could not resolve com.android.support:appcompat-v7:26.1.0.
  Required by:
      project :app</p>
  
  <blockquote>
    <p>Could not resolve com.android.support:appcompat-v7:26.1.0.
    Could not get resource '<a href="https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom" rel="nofollow noreferrer">https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom</a>'.
    Could not GET '<a href="https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom" rel="nofollow noreferrer">https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.pom</a>'.
    Connect to dl.google.com:443 [dl.google.com/127.0.1.2] failed: Connection refused: connect
    Connection refused: connect</p>
  </blockquote>
  
  <p>===============================================
  android studio version is 3.0.1</p>
  
  <p>the last error description:
  Connect to dl.google.com:443 [dl.google.com/127.0.1.2] failed: Connection refused: connect</p>
  
  <blockquote>
    <p>Connection refused: connect</p>
  </blockquote>
  
  <p>I had tried to add google() or maven{http://....} to build.gradle,it's not work as well. how to reslove it? thank you</p>
  
  <p>=======================
  build.gradle(Project):</p>
  
  <pre><code>// Top-level build file where you can add configuration options common to all sub-projects/modules.
  
  
  
  buildscript {
  repositories {
      google()
      jcenter()
  }
  
  dependencies {
      classpath 'com.android.tools.build:gradle:3.0.1'
  
  
      // NOTE: Do not place your application dependencies here; they belong
      // in the individual module build.gradle files
  }
  </code></pre>
  
  <p>}</p>
  
  <pre><code>allprojects {
  repositories {
      google()
      jcenter()
  }
  </code></pre>
  
  <p>}</p>
  
  <pre><code> task clean(type: Delete) {
    delete rootProject.buildDir
   }
  </code></pre>
  
  <p>=============================
  build.gradle(Module):</p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
  compileSdkVersion 26
  defaultConfig {
      applicationId "onlineconfig.umeng.gametools.com.myapplication"
      minSdkVersion 15
      targetSdkVersion 26
      versionCode 1
      versionName "1.0"
      testInstrumentationRunner       
  
  "android.support.test.runner.AndroidJUnitRunner"
  }
  buildTypes {
  
   release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'),     
  
  'proguard-rules.pro'
      }
  }
  }
  
  dependencies {
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  implementation 'com.android.support:appcompat-v7:26.1.0'
  implementation 'com.android.support.constraint:constraint-layout:1.0.2'
  implementation 'com.android.support:design:26.1.0'
  testImplementation 'junit:junit:4.12'
  androidTestImplementation 'com.android.support.test:runner:1.0.1'
  
   androidTestImplementation 'com.android.support.test.espresso:espresso-         
  
  core:3.0.1'
  </code></pre>