在 build.gradle 文件中添加 buildFeatures 时出错

我正在尝试 compose，这是 Andorid jetpack 中的一项新功能.下面是我的代码.我在 app 的 build.gradle 文件中添加 buildfeatures，而不是在根文件夹中.

I am trying out compose which is a new feature in Andorid jetpack. Below is my code. I am adding buildfeatures in build.gradle file of app, not in the root folder.

android {
    compileSdkVersion compileSDKVer
    buildToolsVersion buildToolsVer
    defaultConfig {
        applicationId "com.sample.slothyhacker.jetpackcompose"
        minSdkVersion minSdkVer
        targetSdkVersion targetSdkVer
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

    buildFeatures {
        // Enables Jetpack Compose for this module
        //compose true
    }

    compileOptions {
        // Set both the Java and Kotlin compilers to target Java 8.
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
}

但是我的项目给了我一个编译错误.如果有人能指出我做错了什么，我将不胜感激.

But my project is giving me a compile error. I would really appreciate if someone can put some light on what am doing wrong.

Could not find method buildFeatures() for arguments [build_7yf57wk394cperk1t82v120yf$_run_closure1$_closure5@78c292be] on object of type com.android.build.gradle.internal.dsl.BaseAppModuleExtension.