Failed to resolve: com.android.support:appcompat-v7:28.+

Andriod Studio报错提示：

Error:(26, 13) Failed to resolve: com.android.support:appcompat-v7:28.+

原因：Andriod Studio所使用的sdk版本与build.gradle配置文件中的配置不符，

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-v7:28.+'
    testCompile 'junit:junit:4.12'
}

通过sdk manager查看sdk版本为下图红色部分，即26.1.1
Failed to resolve: com.android.support:appcompat-v7:28.+ 将 com.android.support:appcompat-v7:28.+ 中28 改为26，如下图，即可编译通过