应用程序运行时节省能源

Question

我是 android 编程新手。我编写了一个应用程序，它读取传感器数据（陀螺仪和加速度计），并且在传递值时应该做一些事情。 现在我的问题是电池只运行一小时，sensor_delay_fastest 和sensor_delay_game 之间没有区别。 是否有可能关闭屏幕灯以节省能源，或者我应该将此应用程序作为服务运行，还是有另一种可能性？我也试过SCREEN_DIM_WAKE_LOCK，没有明显效果。

感谢帮助

古纳尔

Answer 1

您可能将电池消耗归咎于错误的罪魁祸首。 电池消耗的最大恶棍是不在您的主应用循环中使用 Thread.sleep(int ms)。

您的主循环可能每秒运行数千次，而实际上实施帧限制可以将次数减少到 24-60（对于流畅的动画），或者对于非常基本的应用程序甚至可以低至 10-20。

考虑一下：如果你不让你的线程休眠，你实际上是在让你的应用程序（和主循环）尽可能快地运行尽可能多的次数。如果没有睡眠，您的应用会消耗 100% 的可用资源来运行，即使它实际上什么也没做。

Here's a good starting tutorial，这是一个实现示例（来自链接）。不要紧张它有多长；没有 cmets 会短很多...

public void run() {
    Canvas canvas;
    Log.d(TAG, "Starting game loop");
    // initialise timing elements for stat gathering
    initTimingElements();

    long beginTime;     // the time when the cycle begun
    long timeDiff;      // the time it took for the cycle to execute
    int 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 surface
        try {
            canvas = this.surfaceHolder.lockCanvas();
            synchronized (surfaceHolder) {
                beginTime = System.currentTimeMillis();
                framesSkipped = 0;  // resetting the frames skipped
                // update game state 
                this.gamePanel.update();
                // render state to the screen
                // draws the canvas on the panel
                this.gamePanel.render(canvas);              
                // calculate how long did the cycle take
                timeDiff = System.currentTimeMillis() - beginTime;
                // calculate sleep time
                sleepTime = (int)(FRAME_PERIOD - timeDiff);

                if (sleepTime > 0) {
                    // if sleepTime > 0 we're OK
                    try {
                        // send the thread to sleep for a short period
                        // very useful for battery saving
                        Thread.sleep(sleepTime);    
                    } catch (InterruptedException e) {}
                }

                while (sleepTime < 0 && framesSkipped < MAX_FRAME_SKIPS) {
                    // we need to catch up
                    this.gamePanel.update(); // update without rendering
                    sleepTime += FRAME_PERIOD;  // add frame period to check if in next frame
                    framesSkipped++;
                }

                if (framesSkipped > 0) {
                    Log.d(TAG, "Skipped:" + framesSkipped);
                }
                // for statistics
                framesSkippedPerStatCycle += framesSkipped;
                // calling the routine to store the gathered statistics
                storeStats();
            }
        } finally {
            // in case of an exception the surface is not left in 
            // an inconsistent state
            if (canvas != null) {
                surfaceHolder.unlockCanvasAndPost(canvas);
            }
        }   // end finally
    }
}