首页 / 移动开发 / Android / Android基本游戏循环实例分析

// desired fpsprivate final static intMAX_FPS = 50;// maximum number of frames to be skippedprivate final static intMAX_FRAME_SKIPS = 5;// the frame periodprivate final static intFRAME_PERIOD = 1000 / MAX_FPS; @Overridepublic void run（） {Canvas canvas;Log.d（TAG, "Starting game loop"）;long beginTime; // the time when the cycle begunlong timeDiff; // the time it took for the cycle to executeint sleepTime; // ms to sleep （<0 if we"re behind）int framesSkipped; // number of frames being skipped sleepTime = 0;while （running） {canvas = null;// try locking the canvas for exclusive pixel editing// in the surfacetry {canvas = this.surfaceHolder.lockCanvas（）;synchronized （surfaceHolder） {beginTime = System.currentTimeMillis（）;framesSkipped = 0; // resetting the frames skipped// update game statethis.gamePanel.update（）;// render state to the screen// draws the canvas on the panelthis.gamePanel.render（canvas）;// calculate how long did the cycle taketimeDiff = System.currentTimeMillis（） - beginTime;// calculate sleep timesleepTime = （int）（FRAME_PERIOD - timeDiff）;if （sleepTime > 0） {// if sleepTime > 0 we"re OKtry {// send the thread to sleep for a short period// very useful for battery savingThread.sleep（sleepTime）;} catch （InterruptedException e） {}}while （sleepTime < 0 && framesSkipped < MAX_FRAME_SKIPS） {// we need to catch up// update without renderingthis.gamePanel.update（）;// add frame period to check if in next framesleepTime += FRAME_PERIOD;framesSkipped++;}}} finally {// in case of an exception the surface is not left in// an inconsistent stateif （canvas ！= null） {surfaceHolder.unlockCanvasAndPost（canvas）;}}// end finally}}