Failed to resolve: com.android.support:appcompat-v7:27.+ 报错解决方法
app module build.gradle dependencies中默认配置如下: dependencies { compile fileTree(dir: 'libs', include: [ '*.jar']) androidTestCompile( 'com.android.support.test.espresso:espresso-core:2.2.2', { exclude group: 'com.android.support', module: 'support-annotations' }) compile 'com.android.support:appcompat-v7:27.+' compile 'com.android.support.constraint:constraint-layout:1.0.2' testCompile 'junit:junit:4.12' } Studio 2.3版本应该在Root Project build.gradle allprojects配置如下: allprojects { repositories { jcenter() maven { url "https://maven.google.com" } } } Studio 3.0版本应该在Root Project build.gradle