java - 带有 StartApp 的 libGDX

Question

我正在使用 libGDX 框架，当我尝试将一个类传递给初始化语句的应用程序监听器时出现此错误:

    01-04 15:43:13.046: D/SensorManager(19487): onAccuracyChanged :: accuracy = 3
01-04 15:43:38.032: D/ActivityThread(2757): setTargetHeapUtilization:0.25
01-04 15:43:38.032: D/ActivityThread(2757): setTargetHeapIdealFree:8388608
01-04 15:43:38.032: D/ActivityThread(2757): setTargetHeapConcurrentStart:2097152
01-04 15:43:38.373: W/dalvikvm(2757): threadid=1: thread exiting with uncaught exception (group=0x4159a438)
01-04 15:43:38.383: E/AndroidRuntime(2757): FATAL EXCEPTION: main
01-04 15:43:38.383: E/AndroidRuntime(2757): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.audiack.freetappgame/com.audiack.freetappgame.MainActivity}: java.lang.NullPointerException
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread.access$700(ActivityThread.java:143)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.os.Looper.loop(Looper.java:137)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread.main(ActivityThread.java:4950)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at java.lang.reflect.Method.invokeNative(Native Method)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at java.lang.reflect.Method.invoke(Method.java:511)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at dalvik.system.NativeStart.main(Native Method)
01-04 15:43:38.383: E/AndroidRuntime(2757): Caused by: java.lang.NullPointerException
01-04 15:43:38.383: E/AndroidRuntime(2757):     at com.audiack.freetappgame.StartAppHandler.showAds(StartAppHandler.java:13)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at Screens.FreeTappGame.<init>(FreeTappGame.java:25)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at com.audiack.freetappgame.MainActivity.onCreate(MainActivity.java:24)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.Activity.performCreate(Activity.java:5179)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
01-04 15:43:38.383: E/AndroidRuntime(2757):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
01-04 15:43:38.383: E/AndroidRuntime(2757):     ... 11 more

我试图将一个带有接口(interface)的类传递给 ApplicationListener 的构造函数，这样我就可以从 libGDX 通用框架访问 android 广告方法。

这是 Activity 类:

package com.audiack.freetappgame;

import Screens.FreeTappGame;
import android.os.Bundle;

import com.badlogic.gdx.backends.android.AndroidApplication;
import com.badlogic.gdx.backends.android.AndroidApplicationConfiguration;
import com.badlogic.gdx.graphics.Texture;
import com.searchboxsdk.android.StartAppSearch;
import com.startapp.android.publish.StartAppAd;

public class MainActivity extends AndroidApplication{
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        AndroidApplicationConfiguration cfg = new AndroidApplicationConfiguration();

        StartAppAd.init(this, "101164873", "201640058");
        StartAppSearch.init(this, "101164873", "201640058");

        Texture.setEnforcePotImages(false);
        cfg.useGL20 = true;
        initialize(new FreeTappGame(new StartAppHandler()), cfg);
    }
}

下面是我想在android端实现的接口(interface):

package UtilityClasses;

public interface StartAppResolver {
    public boolean showAds(boolean show);
}

这里是android项目中实现接口(interface)的类:

package com.audiack.freetappgame;

import UtilityClasses.StartAppResolver;

import com.badlogic.gdx.Gdx;
import com.startapp.android.publish.StartAppAd;

public class StartAppHandler implements StartAppResolver{
protected StartAppAd startAppAd;

@Override
public boolean showAds(boolean show) {
    Gdx.app.log("Ad", "ad command will be here");
    return true;
}
}

最后是 ApplicationListener 类:

package Screens;


import UtilityClasses.Assets;
import UtilityClasses.StartAppResolver;

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Game;
import com.badlogic.gdx.Gdx;

public class FreeTappGame extends Game implements ApplicationListener {
    static float Width;
    static float Height;

    public StartAppResolver startAppResolver;

    public SplashScreen splash_screen;
    public MenuScreen menu_screen;
    public GameScreen game_screen;
    public HighscoreScreen highscore_screen;
    public AboutScreen about_screen;

    public FreeTappGame(StartAppResolver startAppResolver) {
        this.startAppResolver = startAppResolver;
        startAppResolver.showAds(true);
    }

    @Override
    public void create() {
        Width = Gdx.graphics.getWidth();
        Height = Gdx.graphics.getHeight(); 
        Assets.load();

        splash_screen = new SplashScreen(this);
        menu_screen = new MenuScreen(this);
        game_screen = new GameScreen(this);
        highscore_screen = new HighscoreScreen(this);
        about_screen = new AboutScreen(this);

        setScreen(splash_screen);
    }

}

我是不是用错了方法？我不确定如何使用 libGDX 访问广告方法，这是我的最终目标。

Answer 1

我认为这一行导致了您的 NullPointerException:

Gdx.app.log("Ad", "ad command will be here");

那是因为您在初始化 GDX 库之前创建了 FreeTappGame 对象，所以当调用此方法时，Libgdx 尚未初始化 Gdx.app 全局。