main.xml中的GLSurfaceView空指針異常

Question

我正在嘗試使glsurfaceview成為我的布局的一部分。 它在我確定的一行上返回錯誤，但我不明白為什么。 我的GLGame類：

public abstract class GLGame extends Activity implements Game, Renderer {
    enum GLGameState {
        Initialized,
        Running,
        Paused,
        Finished,
        Idle
    }

    GLSurfaceView glView;    
    GLGraphics glGraphics;
    Audio audio;
    Input input;
    FileIO fileIO;
    Screen screen;
    GLGameState state = GLGameState.Initialized;
    Object stateChanged = new Object();
    long startTime = System.nanoTime();
    WakeLock wakeLock;

    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                             WindowManager.LayoutParams.FLAG_FULLSCREEN);
        glView =(GLSurfaceView) this.findViewById (R.id.glSurface);
        glView.setRenderer(this); //Failing line
        setContentView(R.layout.main); 

        glGraphics = new GLGraphics(glView);
        fileIO = new AndroidFileIO(getAssets());
        audio = new AndroidAudio(this);
        input = new AndroidInput(this, glView, 1, 1);
        PowerManager powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
        wakeLock = powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, "GLGame");        
    }

    public void onResume() {
        super.onResume();
        glView.onResume();
        wakeLock.acquire();
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {        
        glGraphics.setGL(gl);

        synchronized(stateChanged) {
            if(state == GLGameState.Initialized)
                screen = getStartScreen();
            state = GLGameState.Running;
            screen.resume();
            startTime = System.nanoTime();
        }        
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {        
    }

    @Override
    public void onDrawFrame(GL10 gl) {                
        GLGameState state = null;

        synchronized(stateChanged) {
            state = this.state;
        }

        if(state == GLGameState.Running) {
            float deltaTime = (System.nanoTime()-startTime) / 1000000000.0f;
            startTime = System.nanoTime();

            screen.update(deltaTime);
            screen.present(deltaTime);
        }

        if(state == GLGameState.Paused) {
            screen.pause();            
            synchronized(stateChanged) {
                this.state = GLGameState.Idle;
                stateChanged.notifyAll();
            }
        }

        if(state == GLGameState.Finished) {
            screen.pause();
            screen.dispose();
            synchronized(stateChanged) {
                this.state = GLGameState.Idle;
                stateChanged.notifyAll();
            }            
        }
    }   

    @Override 
    public void onPause() {        
        synchronized(stateChanged) {
            if(isFinishing())            
                state = GLGameState.Finished;
            else
                state = GLGameState.Paused;
            while(true) {
                try {
                    stateChanged.wait();
                    break;
                } catch(InterruptedException e) {         
                }
            }
        }
        wakeLock.release();
        glView.onPause();  
        super.onPause();
    }    

    public GLGraphics getGLGraphics() {
        return glGraphics;
    }  

    @Override
    public Input getInput() {
        return input;
    }

    @Override
    public FileIO getFileIO() {
        return fileIO;
    }

    @Override
    public Graphics getGraphics() {
        throw new IllegalStateException("We are using OpenGL!");
    }

    @Override
    public Audio getAudio() {
        return audio;
    }

    @Override
    public void setScreen(Screen screen) {
        if (screen == null)
            throw new IllegalArgumentException("Screen must not be null");

        this.screen.pause();
        this.screen.dispose();
        screen.resume();
        screen.update(0);
        this.screen = screen;
    }

    @Override
    public Screen getCurrentScreen() {
        return screen;
    }
}

Logcat：

03-25 16:44:51.683    4919-4919/com.badlogic.androidgames.glbasics E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.badlogic.androidgames.glbasics, PID: 4919
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.badlogic.androidgames.glbasics/com.badlogic.androidgames.glbasics.GLGameTest}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.opengl.GLSurfaceView.setRenderer(android.opengl.GLSurfaceView$Renderer)' on a null object reference
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2329)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
            at android.app.ActivityThread.access$900(ActivityThread.java:147)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5256)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.opengl.GLSurfaceView.setRenderer(android.opengl.GLSurfaceView$Renderer)' on a null object reference
            at com.badlogic.androidgames.framework.impl.GLGame.onCreate(GLGame.java:51)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2282)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
            at android.app.ActivityThread.access$900(ActivityThread.java:147)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5256)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:898)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)

一切正常，直到我決定除glsurfaceview之外還需要其他東西。

我認為我只是在犯一個愚蠢的錯誤，但是由於時間緊迫，如果您能提供幫助，我將感到非常高興。

謝謝

編輯：問題原來是由於某種原因我無法從這里找到viewbyid。 我也試過這個：

  GLGame.glView = (GLSurfaceView) ((Activity)getApplicationContext()).findViewById (R.id.glSurface);

Answer 1

事實證明，我以錯誤的順序寫書簡直是愚蠢。 應該是這樣的：

       setContentView(R.layout.main);
    GLGame.glView = (GLSurfaceView) this.findViewById(R.id.glSurface);
    glView.setRenderer(this);