Java 为什么触摸屏幕时我的性能会提高？

由于某些原因，当我按住鼠标左键在屏幕上（在模拟器上）移动鼠标时，我的FPS会大幅提升。通常我的游戏很慢，但如果我触摸屏幕（只要我在触摸时移动鼠标），它就会非常流畅

我试着在onTouchEvent中睡20毫秒，但似乎没有任何区别

以下是我在onTouchEvent中使用的代码：

 // events when touching the screen
    public boolean onTouchEvent(MotionEvent event) 
    {
        int eventaction = event.getAction(); 

        touchX=event.getX();
        touchY=event.getY();

        switch (eventaction) 
        { 
         case MotionEvent.ACTION_DOWN: 
         {
          touch=true;
         }
         break; 

         case MotionEvent.ACTION_MOVE:
         {

         }
         break; 

         case MotionEvent.ACTION_UP: 

         {
          touch=false;
         }
              break; 
        }

     /*try 
     {
      AscentThread.sleep(20);
     } 
     catch (InterruptedException e) 
     {
      // TODO Auto-generated catch block
      e.printStackTrace();
     }*/

        return true; 
    }

在logcat日志中，FPS是当前FPS（最后20帧的平均值），touch是指是否触摸屏幕（从onTouchEvent）

到底发生了什么事？以前还有其他人有过这种奇怪的行为吗

Logcat日志：

12-21 19:43:26.154: INFO/myActivity(786): FPS: 31.686569159606414 Touch: false
12-21 19:43:27.624: INFO/myActivity(786): FPS: 19.46310293212206 Touch: false
12-21 19:43:29.104: INFO/myActivity(786): FPS: 18.801202175690467 Touch: false
12-21 19:43:30.514: INFO/myActivity(786): FPS: 21.118295877408478 Touch: false
12-21 19:43:31.985: INFO/myActivity(786): FPS: 19.117397812958878 Touch: false
12-21 19:43:33.534: INFO/myActivity(786): FPS: 15.572571858239263 Touch: false
12-21 19:43:34.934: INFO/myActivity(786): FPS: 20.584119901503506 Touch: false
12-21 19:43:36.404: INFO/myActivity(786): FPS: 18.888025905454207 Touch: false
12-21 19:43:37.814: INFO/myActivity(786): FPS: 22.35722329083629 Touch: false
12-21 19:43:39.353: INFO/myActivity(786): FPS: 15.73604859775362 Touch: false
12-21 19:43:40.763: INFO/myActivity(786): FPS: 20.912449882754633 Touch: false
12-21 19:43:42.233: INFO/myActivity(786): FPS: 18.785278388997718 Touch: false
12-21 19:43:43.634: INFO/myActivity(786): FPS: 20.1357397209596 Touch: false
12-21 19:43:45.043: INFO/myActivity(786): FPS: 21.961138432007957 Touch: false
12-21 19:43:46.453: INFO/myActivity(786): FPS: 22.167196852834273 Touch: false
12-21 19:43:47.854: INFO/myActivity(786): FPS: 22.207318228024274 Touch: false
12-21 19:43:49.264: INFO/myActivity(786): FPS: 22.36980559230175 Touch: false
12-21 19:43:50.604: INFO/myActivity(786): FPS: 23.587638823252547 Touch: false
12-21 19:43:52.073: INFO/myActivity(786): FPS: 19.233902040593076 Touch: false
12-21 19:43:53.624: INFO/myActivity(786): FPS: 15.542190150440987 Touch: false
12-21 19:43:55.034: INFO/myActivity(786): FPS: 20.82290063974675 Touch: false
12-21 19:43:56.436: INFO/myActivity(786): FPS: 21.975282007207717 Touch: false
12-21 19:43:57.914: INFO/myActivity(786): FPS: 18.786927284103687 Touch: false
12-21 19:43:59.393: INFO/myActivity(786): FPS: 18.96879004217992 Touch: false
12-21 19:44:00.625: INFO/myActivity(786): FPS: 28.367566618064878 Touch: false
12-21 19:44:02.113: INFO/myActivity(786): FPS: 19.04441528684418 Touch: false
12-21 19:44:03.585: INFO/myActivity(786): FPS: 18.807837511809065 Touch: false
12-21 19:44:04.993: INFO/myActivity(786): FPS: 21.134330284993418 Touch: false
12-21 19:44:06.275: INFO/myActivity(786): FPS: 27.209688764079907 Touch: false
12-21 19:44:07.753: INFO/myActivity(786): FPS: 19.055894653261653 Touch: false
12-21 19:44:09.163: INFO/myActivity(786): FPS: 22.05422794901088 Touch: false
12-21 19:44:10.644: INFO/myActivity(786): FPS: 18.6956805300596 Touch: false
12-21 19:44:12.124: INFO/myActivity(786): FPS: 17.434180581311054 Touch: false
12-21 19:44:13.594: INFO/myActivity(786): FPS: 18.71932038510891 Touch: false
12-21 19:44:14.504: INFO/myActivity(786): FPS: 40.94571503868066 Touch: true
12-21 19:44:14.924: INFO/myActivity(786): FPS: 57.061200121138576 Touch: true
12-21 19:44:15.364: INFO/myActivity(786): FPS: 62.54377946377936 Touch: true
12-21 19:44:15.764: INFO/myActivity(786): FPS: 64.05005071818726 Touch: true
12-21 19:44:16.384: INFO/myActivity(786): FPS: 50.912951172948155 Touch: true
12-21 19:44:16.874: INFO/myActivity(786): FPS: 55.31242053078078 Touch: true
12-21 19:44:17.364: INFO/myActivity(786): FPS: 59.31625410615102 Touch: true
12-21 19:44:18.413: INFO/myActivity(786): FPS: 36.63504170925923 Touch: false
12-21 19:44:19.885: INFO/myActivity(786): FPS: 18.099130467755923 Touch: false
12-21 19:44:21.363: INFO/myActivity(786): FPS: 18.458978222946566 Touch: false
12-21 19:44:22.683: INFO/myActivity(786): FPS: 25.582179409330823 Touch: true
12-21 19:44:23.044: INFO/myActivity(786): FPS: 60.99865521942455 Touch: true
12-21 19:44:23.403: INFO/myActivity(786): FPS: 74.17873975470984 Touch: true
12-21 19:44:23.763: INFO/myActivity(786): FPS: 64.25663040460714 Touch: true
12-21 19:44:24.113: INFO/myActivity(786): FPS: 62.47483457826921 Touch: true
12-21 19:44:24.473: INFO/myActivity(786): FPS: 65.27969529547072 Touch: true
12-21 19:44:24.825: INFO/myActivity(786): FPS: 67.84743115273311 Touch: true
12-21 19:44:25.173: INFO/myActivity(786): FPS: 73.50854551357706 Touch: true
12-21 19:44:25.523: INFO/myActivity(786): FPS: 70.46432534585368 Touch: true
12-21 19:44:25.873: INFO/myActivity(786): FPS: 69.04076953445896 Touch: true

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如果您在Windows上运行emulator，那么我想可以解释一下：

中的性能选项说明 Windows

。。。另外，请记住Microsoft Windows NT还使用额外的优先级 基于其他因素的调整（通常为2） 事件，例如瞬间提升 线程从返回时的优先级 从服务器返回时的I/O调用 用户模式子系统调用，或 接收键盘输入

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这种效果我已经见过很多次了。我只是浏览了一下使用ProcessExplorer的仿真器：虽然我不能肯定，但它看起来像是在单个Windows线程下运行的。除非你在真正的Android设备上看到类似的性能提升，否则我认为这是Windows操作系统的影响，而不是AndroidOS。

我也遇到了同样的问题，而且手机上也出现了同样的问题，尽管这个问题不太明显。我想我知道发生了什么。我在主循环中使用带有postDelayed（…）的处理程序。我猜绘图首先会以某种方式阻塞消息队列，然后touchevent会导致应用程序在下次计划检查之前检查队列。为什么这个问题会随机发生是个谜

我通过在Runnable中把延迟后的行放在绘图之前解决了这个问题

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它肯定与Windows无关。

只是一个猜测，但在活动量较低时，处理器是否会动态地改变其速度，作为一种节能措施？（即SpeedStep）嗯，说得好，我来看看。你的游戏循环是什么样子的？你有一个专门的渲染线程吗，或者你是从onDraw（）的末尾开始使（）无效？谢谢你，这让我非常恼火。