android - 模拟器一直崩溃

Question

为什么我不断收到此错误:当我单击菜单上的“开始”按钮时，它应该绘制游戏背景，但模拟器却显示“不幸的是，应用程序已停止”。

这是 LogCat:

12-20 15:52:35.440: D/dalvikvm(941): Not late-enabling CheckJNI (already on) 
12-20 15:52:37.380: D/dalvikvm(941): GC_FOR_ALLOC freed 54K, 4% free 3158K/3288K, paused 29ms, total 30ms
12-20 15:52:37.530: D/gralloc_goldfish(941): Emulator without GPU emulation detected.
12-20 15:51:47.789: D/dalvikvm(941): GC_FOR_ALLOC freed 44K, 4% free 3625K/3744K, paused 53ms, total 58ms
12-20 15:51:47.859: D/AndroidRuntime(941): Shutting down VM
12-20 15:51:47.859: W/dalvikvm(941): threadid=1: thread exiting with uncaught exception (group=0xb3a95b90)
12-20 15:51:47.889: E/AndroidRuntime(941): FATAL EXCEPTION: main
12-20 15:51:47.889: E/AndroidRuntime(941): Process: com.jfdimarzio, PID: 941 
12-20 15:51:47.889: E/AndroidRuntime(941): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.jfdimarzio/com.jfdimarzio.PBGame}: java.lang.NullPointerException
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread.access$700(ActivityThread.java:135)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.os.Handler.dispatchMessage(Handler.java:102)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.os.Looper.loop(Looper.java:137)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread.main(ActivityThread.java:4998)
12-20 15:51:47.889: E/AndroidRuntime(941):  at java.lang.reflect.Method.invokeNative(Native Method) 
12-20 15:51:47.889: E/AndroidRuntime(941):  at java.lang.reflect.Method.invoke(Method.java:515)
12-20 15:51:47.889: E/AndroidRuntime(941):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
12-20 15:51:47.889: E/AndroidRuntime(941):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
12-20 15:51:47.889: E/AndroidRuntime(941):  at dalvik.system.NativeStart.main(Native Method) 
12-20 15:51:47.889: E/AndroidRuntime(941): Caused by: java.lang.NullPointerException
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.view.ViewGroup.addViewInner(ViewGroup.java:3561)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.view.ViewGroup.addView(ViewGroup.java:3415)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.view.ViewGroup.addView(ViewGroup.java:3391)
12-20 15:51:47.889: E/AndroidRuntime(941):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:309)
12-20 15:51:47.889: E/AndroidRuntime(941):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:299)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.Activity.setContentView(Activity.java:1948)
12-20 15:51:47.889: E/AndroidRuntime(941):  at com.jfdimarzio.PBGame.onCreate(PBGame.java:14)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.Activity.performCreate(Activity.java:5243)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
12-20 15:51:47.889: E/AndroidRuntime(941):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
12-20 15:51:47.889: E/AndroidRuntime(941):  ... 11 more 
12-20 15:51:53.249: I/Process(941): Sending signal. PID: 941 SIG: 9

这是 PBGame.java。你能帮我解决 NullPointerException 吗？ (PBGame是新 Activity )

import android.app.Activity;
import android.os.Bundle;

public class PBGame extends Activity {
    final PBGameVars gameEngine = new PBGameVars();
    private PBGameView gameView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(gameView);
    }

    @Override
    protected void onResume() {
        super.onResume();
        gameView.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        gameView.onPause();
    }

}

Answer 1

来自 documentation ，您通常会调用 setContentView(int) 和定义您的 UI 的布局资源。

所以，应该是

setContentView(R.layout.gameView);

并删除 gameView.onResume(); 和 gameView.onPause();

和

gameView = new PBGameView(this);// note the this keyword