调试不显示变量在android studio项目？

Question

当我按下“调试”按钮时 在那之后，我在变量中什么都找不到。 Look at the picture 我希望您在玩游戏时会出现这些项目以及+ Like in the picture的元素 ， 我能做什么？

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.ahmed.oop"
        minSdkVersion 17
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }

        debug {
         //   testCoverageEnabled true
            testCoverageEnabled false
            debuggable true

        }

    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    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'
}