How to solve android game Integrated with admob the screen goes empty?

cocos2d-x C++
#1

I use cocos2d-x to write a simple game, i had build and published to Google Play, now i would like to integrated with admob.

I create main.xml file
`<?xml version="1.0" encoding="utf-8"?>

<com.google.ads.AdView android:id="@+id/adView"
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
ads:adUnitId=“my admob publisher id”
ads:adSize=“BANNER”
ads:testDevices=“TEST_EMULATOR, TEST_DEVICE_ID”
ads:loadAdOnCreate=“true”/>
```

I add the AdActivity and permistion in my Manifest file

``````

<uses-permission android:name="android.permission.INTERNET"/> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

And here is the code to load admob

`private AdView adView;

protected void onCreate(Bundle savedInstanceState){
	super.onCreate(savedInstanceState);	
	//add admob advertise
	try
	{
		setContentView(R.layout.main);

		// Create the adView
		adView = new AdView(this, AdSize.BANNER, "my admob publisher id");
		
		adView.setGravity(Gravity.BOTTOM | Gravity.LEFT);
		// Lookup your LinearLayout assuming it's been given
		// the attribute android:id="@+id/mainLayout"
		LinearLayout layout = (LinearLayout)findViewById(R.id.adView);
		adView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
		adView.setVisibility(AdView.VISIBLE);
		// Add the adView to it
		layout.addView(adView);
		// Initiate a generic request to load it with an ad
		adView.loadAd(new AdRequest());
	}
	catch(Exception e)
	{
		Log.d("", "error: " + e);
	}

}

@Override
protected void onDestroy() {
  if (adView != null) {
    adView.destroy();
  }
  super.onDestroy();
}`

I build and export successfully.
When i install to my test smart phone, when i run the game it show an empty screen, my game not run.
I don’t know why, when i test my smart phone don’t have internet.
Could you help me to solve this problem?