1：给Gradle加了点注释。

build.gradle

@@ -7,10 +7,10 @@ buildscript {
     }
 
     dependencies {
+        //classpath "com.android.tools.build:gradle:$localGradlePluginVersion"
+        //$localGradlePluginVersion是gradle.properties中的数据
         classpath "com.android.tools.build:gradle:$localGradlePluginVersion"
         classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
     }
 }
 
@@ -34,6 +34,7 @@ task clean(type: Delete) {
 // Define versions in a single place
 ext {
     // Sdk and tools
+    //localBuildToolsVersion是gradle.properties中的数据
     buildToolsVersion = localBuildToolsVersion
     compileSdkVersion = 25
     minSdkVersion = 15

gradle.properties

@@ -17,9 +17,11 @@ org.gradle.jvmargs=-Xmx1536m
 org.gradle.daemon=true
 org.gradle.configureondemand=true
 org.gradle.parallel=true
+
 # 为自动化出包配置(因为每个开发的电脑坏境不一致)
 localBuildToolsVersion=25.0.2
-localGradlePluginVersion=2.3.0
+# 这个值一般跟你的AndroidStudio版本号一致
+localGradlePluginVersion=2.3.1
 
 # 每次更改“isModule”的值后，需要点击 "Sync Project" 按钮
-isModule=true
+isModule=false