Error : Execution failed for task ’ :app: preDebugAndroidTestBuild’.Conflict with dependency ‘com.android.support:support-annotations’ in project ‘:app’.  Resolved versions for app (26.1.0) and test app (27.1.1) differ. See https://d.android.com/r/tools/test-apk-dependency-conflicts.html for details.

　　

 解决方法

1.修改app version

apply plugin: 'com.android.application'android {    compileSdkVersion 26//27    defaultConfig {        applicationId "com.example.yueli.flightcheck"        minSdkVersion 14        targetSdkVersion 26//27        versionCode 1        versionName "1.0"        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        }    }}dependencies {    implementation fileTree(dir: 'libs', include: ['*.jar'])    implementation 'com.android.support:appcompat-v7:26.1.0'//：27.1.1    implementation 'com.android.support.constraint:constraint-layout:1.1.2'    testImplementation 'junit:junit:4.12'    androidTestImplementation 'com.android.support.test:runner:1.0.2'    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'}

 2.修改app test version

apply plugin: 'com.android.application'android {    compileSdkVersion 26    defaultConfig {        applicationId "com.example.yueli.flightcheck"        minSdkVersion 14        targetSdkVersion 26        versionCode 1        versionName "1.0"        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        }    }}dependencies {    implementation fileTree(dir: 'libs', include: ['*.jar'])    implementation 'com.android.support:appcompat-v7:26.1.0'    implementation 'com.android.support.constraint:constraint-layout:1.1.2'    testImplementation 'junit:junit:4.12'    androidTestImplementation 'com.android.support.test:runner:1.0.2'//1.0.1    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'//3.0.1}