报错

Error: Could not find com.android.tools.build:gradle:2.2.1. 
Searched in the following locations: 
file:/D:/software/android/android-studio-ide-145.3276617-windows/android-studio/gradle/m2repository/com/android/tools/build/gradle/2.2.1/gradle-2.2.1.pom 
file:/D:/software/android/android-studio-ide-145.3276617-windows/android-studio/gradle/m2repository/com/android/tools/build/gradle/2.2.1/gradle-2.2.1.jar 
https://jcenter.bintray.com/com/android/tools/build/gradle/2.2.1/gradle-2.2.1.pom 
https://jcenter.bintray.com/com/android/tools/build/gradle/2.2.1/gradle-2.2.1.jar

解决方法：进入%android-studio安装目录%\gradle\m2repository\com\android\tools\build\gradle

将项目中的build.gradle文件中

dependencies {
        classpath 'com.android.tools.build:gradle:2.2.1'
}

改为

dependencies {
        classpath 'com.android.tools.build:gradle:2.2.0'
}

即可。

注意：gradle的版本指的是仓库中的gradle编译工具版本，不是gradle版本。

再补充一点

build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}
allprojects {
    repositories {
        jcenter()
    }
}

android {
    compileSdkVersion 23
    buildToolsVersion '23.0.3'
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }
}
dependencies {
}

中

android { buildToolsVersion ‘23.0.3’ }

这个是在sdk的build-tools目录下

引用：Android Studio Error:Could not find com.android.tools.build:gradle