Question

我正在使用Robert Green GLWallpaperService jar文件开发openGL动态壁纸。运行代码后没有壁纸做蚂蚁绘制任务屏幕----

02-16 11:09:31.941: E/AndroidRuntime(6286): FATAL EXCEPTION: GLThread 9
02-16 11:09:31.941: E/AndroidRuntime(6286): java.lang.NullPointerException
02-16 11:09:31.941: E/AndroidRuntime(6286): at com.inoxmobile.waterlwp.WaterLiveWallpaperRenderer.onDrawFrame(WaterLiveWallpaperRenderer.java:152)
02-16 11:09:31.941: E/AndroidRuntime(6286): at    
com.inoxmobile.waterlwp.GLThread.guardedRun(GLWallpaperService.java:683)    
02-16 11:09:31.941: E/AndroidRuntime(6286):at com.inoxmobile.waterlwp.GLThread.run(GLWallpaperService.java:541)

我正在使用此代码-----

public void onDrawFrame(GL10 gl)
  {

    if (gl == null)
        return;

    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);    

    gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
    gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);
    gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

    if (usebg) {
        gl.glDepthMask(false);
        mBackground.draw(gl);//Exception come Here..........
        gl.glDepthMask(true);
    }

    gl.glMatrixMode(GL10.GL_MODELVIEW);
    gl.glLoadIdentity();    

    //if (usebg){
        //mBackground.Init(gl);
        //mBackground.setDims(mWidth, mHeight);
    //}
}

Answer 1

您确定已在mBackground或此类的构造函数中初始化onCreate()吗？请记住，如果您只有成员声明，

private Background mBackground;

这相当于

private Background mBackground = null;

为什么会出现NullPointerException？

1 个答案: