小编Lot*_*akz的帖子

我正在尝试导入这个： import android.support.v7.widget.RecyclerView;

但我明白了：“无法解析symbole v7”。

确实，当我打字时，android.support.我可以选择 v4 但不能选择 v7

这是我的 build.gradle ：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.bibstandardandroidstudio"
        minSdkVersion 23
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    buildToolsVersion '28.0.3'
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'androidx.appcompat:appcompat:1.1.0-alpha04'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.2.0-alpha03'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0-alpha03'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'org.mindrot:jbcrypt:0.4'
    implementation 'com.android.volley:volley:1.1.1' …