Error:Execution failed for task ':app:preDebugAndroidTestBuild'. > Conflict with dependency

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//
    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'//：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
}