方式一：
1. 在cocos2dx编译完成的项目(proj.android)加入 GDTUnionSDK.4.8.524.min.jar广点通jar包。
2. 添加权限声明

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_UPDATES" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<service
        android:name="com.qq.e.comm.DownloadService"
        android:exported="false" />

<activity
<span style="white-space:pre">	</span>android:name="com.qq.e.ads.ADActivity"
        android:configChanges="keyboard|keyboardHidden|orientation|screenSize" />

<span style="white-space:pre">	</span>private static Handler mHandler;
	private InterstitialAD iad;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		mHandler = new Handler(){
			public void handleMessage(android.os.Message msg) {
				switch (msg.what) {
				case 1:
					showAD();
					break;
				case 2:
					showAsPopup();
					break;
				case 3:
					closeAsPopup();
					break;

				default:
					break;
				}
			};
			
		};
	}

	private InterstitialAD getIAD() {
		if (iad == null) {
			iad = new InterstitialAD(this,Constants.APPID,Constants.InterteristalPosID);
		}
		return iad;
	}

	private void showAD() {
		getIAD().setADListener(new AbstractInterstitialADListener() {

			@Override
			public void onNoAD(int arg0) {
				Log.i("longer","LoadInterstitialAd Fail:" + arg0);
			}

			@Override
			public void onADReceive() {
				Log.i("longer","onADReceive");
				iad.show();
			}
		});
		iad.loadAD();
	}

	private void showAsPopup() {
		getIAD().setADListener(new AbstractInterstitialADListener() {

			@Override
			public void onNoAD(int arg0) {
				Log.i("longer","LoadInterstitialAd Fail:" + arg0);
			}

			@Override
			public void onADReceive() {
				iad.showAsPopupWindow();
			}
		});
		iad.loadAD();
	}

	private void closeAsPopup() {
		iad.closePopupWindow();
	}

<span style="white-space:pre">	</span>/**
	 * c++中調用的方法
	 * @param what    1: 使用showAD方式展示插屏广告
	 * 				  2: 使用showAsPopup方式展示广告
	 * 				  3: 关闭popup广告
	 */
	public static void showAd(int what) {
		mHandler.sendEmptyMessage(what);
	}

.h文件

#ifndef GDTAD_H  
#define GDTAD_H  

class GDTAD {
public:
	/*
		what 1 -- 10  插屏广告， 1 ： 显示
		what 11 -- 20 ......， 11： 显示
		what 21 -- 30 ......， 21： 显示
	*/
	static void showAd(int what);
};

#endif //GDTAD_H  

#include "GDTAD.h"
#include "cocos2d.h"
USING_NS_CC;

#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)
#include "platform/android/jni/JniHelper.h"
#include <jni.h>

const char* AppActivityCalssName = "org/cocos2dx/cpp/AppActivity";

void GDTAD::showAd(int what) {
	cocos2d::JniMethodInfo jniShowAd;
	if (cocos2d::JniHelper::getStaticMethodInfo(jniShowAd,AppActivityCalssName,"showAd","(I)V")) {
		jniShowAd.env->CallStaticVoidMethod(jniShowAd.classID,jniShowAd.methodID,what);
	}
	else {
		log("jni:showAD false");
	}
}

#else
void GDTAD::showAd(int what) {
	log("jni:showAD");
	return;
}

#endif

6. 在想要显示广告的地方调用GDTAD类的静态方法showAd进行广告的显示。

GDTAD::showAd(1);