解决Android Studio Gradle DSL method not found: 'android()'问题

android {
compileSdkVersion 19
buildToolsVersion 23.0.2
}

build.gradle:

buildscript {
repositories {
mavenCentral()
}

dependencies {
classpath 'com.android.tools.build:gradle:2.0.0'
}
}

allprojects {
repositories {
mavenCentral()
}
}

app/build.gradle:

apply plugin: 'com.android.application'

android {
compileSdkVersion 23
buildToolsVersion '23.0.3'

defaultConfig {
minSdkVersion 9
targetSdkVersion 23
versionCode 1
versionName '1.0'
}
}

dependencies {
compile 'com.android.support:appcompat-v7:23.2.1'
}
Then run gradle:
gradle installDebug