Android studio gradle build无限运行

Question

我在build.gradle文件中将compileSdkVersion，targetSdkVersion和依赖项从26更改为27并单击了同步按钮。

这是我的问题。 gradle构建运行永远不会结束。我已经等了好几个小时了。

当我运行项目时也会出现此问题。

问题的原因是什么？

build.gradle（模块：应用）

tooltips: { to: function().... }

的build.gradle（项目）

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.gywjd.comprehensivedesign"
        minSdkVersion 21
        targetSdkVersion 27
        multiDexEnabled true
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        debug {
            crunchPngs false
            ext.enableCrashlytics = false
            ext.alwaysUpdateBuildId = false
            minifyEnabled true
            useProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),
                'proguard-rules.pro'
        }
        release {
            minifyEnabled true
            crunchPngs false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    dexOptions {
        jumboMode true
        maxProcessCount 4 // this is the default value
        javaMaxHeapSize "4g"
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:multidex:1.0.2'
    implementation 'com.android.support:appcompat-v7:27.0.2'
    implementation 'com.android.support:design:27.0.2'
    implementation  'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}

VMoptions

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'

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

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

gradle.properties

# custom Android Studio VM options, see             
https://developer.android.com/studio/intro/studio-config.html
-Xms3g
-Xmx7g
-XX:MaxPermSize=1024m
-XX:ReservedCodeCacheSize=1024m
-XX:+UseCompressedOops