缺少必需的XML属性"adSize"

因此,出于某种原因,当我放入广告时,它不会自动填充广告:adSize和ads:adUnitId,我无法选择它们,而我的广告显示的文字显示缺少必需的XML属性"adSize".我也不认为我可以在我的布局中填写xmlns:ads,虽然我可能弄错了.为什么是这样？

我的渐变

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

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.2'
        classpath 'com.google.gms:google-services:3.0.0'

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

allprojects {
    repositories {
        jcenter()
    }
}

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

第二个build.gradle

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.example.matig.adtest"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.1.0'
    testCompile 'junit:junit:4.12'
    compile 'com.google.firebase:firebase-ads:9.0.2'
    compile 'com.google.android.gms:play-services-ads:9.0.2'
}

apply plugin: 'com.google.gms.google-services'

我的布局:

我一步一步地遵循火焰基础教程所以我真的很困惑我做错了什么

将布局与文档中提供的示例进行比较表明您需要添加:

xmlns:ads="http://schemas.android.com/apk/res-auto"

和

ads:adSize="BANNER"