我是Android的初学者，我正在尝试在webview上展示广告但我在布局文件中遇到问题“以下类无法实例化：com.google.android.gms.ads.AdView”。我遵循了使用Google Play服务所涉及的所有步骤。非常感谢你的帮助。
MainActivity.Java
package com.test.webviewcode;
import com.test.webviewcode.R;
import com.google.android.gms.ads.*;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.LinearLayout;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdSize;
import com.google.android.gms.ads.AdView;
import android.app.Activity;
public class MainActivity extends Activity {
private AdView adView;
private WebView mWebView;
private static final String AD_UNIT_ID = "xxxxxxxxxxxxxxxxxxxxxxxxx";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mWebView = (WebView) findViewById(R.id.activity_main_webview);
// Enable Javascript
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mWebView.loadUrl("https://www.google.com/");
// Stop local links and redirects from opening in browser instead of WebView
mWebView.setWebViewClient(new WebViewClient1());
// Create an ad.
adView = new AdView(this);
adView.setAdSize(AdSize.BANNER);
adView.setAdUnitId(AD_UNIT_ID);
LinearLayout Layout = (LinearLayout) findViewById(R.id.adView);
Layout.addView(adView);
AdRequest adRequest = new AdRequest.Builder()
.addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
.addTestDevice("yyyyyyyyyyyyyyyyyyyyyyyyyyy")
.build();
adView.loadAd(adRequest);
}
@Override
public void onBackPressed() {
if(mWebView.canGoBack()) {
mWebView.goBack();
} else {
super.onBackPressed();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onConfigurationChanged(Configuration newConfig){
super.onConfigurationChanged(newConfig);
}
@Override
public void onResume() {
super.onResume();
if (adView != null) {
adView.resume();
}
}
@Override
public void onPause() {
if (adView != null) {
adView.pause();
}
super.onPause();
}
/** Called before the activity is destroyed. */
@Override
public void onDestroy() {
// Destroy the AdView.
if (adView != null) {
adView.destroy();
}
super.onDestroy();
}
}
activity_main.xml中
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.google.android.gms.ads.AdView
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:id="@+id/adView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentTop="false"
android:layout_centerHorizontal="true"
ads:adSize="BANNER"
ads:adUnitId="xxxxxxxxxxxxxxxxxx" >
<!--
ads:loadAdOnCreate="true"
ads:refreshInterval="30" >
-->
</com.google.android.gms.ads.AdView>
<LinearLayout
android:layout_alignParentTop="true"
android:layout_above="@id/adView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ProgressBar
android:id="@+id/ProgressBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:indeterminate="false"
android:progress="50"
android:progressDrawable="@drawable/greenprogress" />
<WebView
android:id="@+id/activity_main_webview"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
</RelativeLayout>
Mainfest文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.test.webviewcode"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="10"
android:targetSdkVersion="21" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<meta-data android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.google.android.gms.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/>
</application>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET" />
</manifest>
答案 0 :(得分：0)
这意味着您尚未在自己的APK中添加Google Play服务库。
请注意，您的代码还存在其他一些基本问题。