找不到Gradle DSL方法：＆＃39; buildToolsVersion（）＆＃39;

Question

我是Android-Studio的新手

因为我导入了facebook和另外一个第三方sdk

但我收到了以下错误

Error:(16, 0) Gradle DSL method not found: 'buildToolsVersion()'
Possible causes:The project 'EmojiShare' may be using a version of Gradle that does not contain the method.
Open Gradle wrapper file, The build file may be missing a Gradle plugin.
Apply Gradle plugin

我的build.gradle文件的代码在

下面

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.2.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

app / build.gradle中的

代码是

apply plugin: 'com.android.application'

android {
    compileSdkVersion 22
    buildToolsVersion "23.0.0 rc2"

    defaultConfig {
        applicationId "emoji.drcsystems.com.emojishare"
        minSdkVersion 22
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {

        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile project(':EmojiconApp')

}