android 中buildToolsVersion和dependencies

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"

    defaultConfig {
        applicationId "com.example.meng.newmessage"
        minSdkVersion 8
        targetSdkVersion 17
    }

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

dependencies {
    //compile 'com.android.support:support-v4:18.+'
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:recyclerview-v7:27.1.1'
}

android {
    compileSdkVersion 17
    buildToolsVersion "26.0.2"

    defaultConfig {
        applicationId "com.example.meng.newmessage"
        minSdkVersion 8
        targetSdkVersion 17
    }

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

dependencies {
    compile 'com.android.support:support-v4:18.+'
}