Android Timer App问题 [英] Android Timer App questions

问题描述

嘿伙计们，我正在通过制作一个简单的应用程序来学习机器人。我想要做的是一个简单的应用程序，每秒钟点亮一个按钮，然后一秒钟灯关闭，如果用户点亮按钮，它点亮它们得到一个点。点亮的按钮取决于随机数生成器。



我正在使用我在ScheduledExecutorService上找到的教程来创建一个计时器，程序输出正确在我添加代码以更新每个tick的标签后，在控制台中但在更新程序后卡住了。下面是代码

  private   final  ScheduledExecutorService scheduler = Executors.newScheduledThreadPool（ 1 ）; 
  public   void  beepForAnHour（）
 {
 
  final  Runnable beeper =  new  Runnable（）
 {
 
 < span class =code-keyword> public   void  run（）
 {
 
  //   int Min = 1;  
  //   int Max = 3;  
  //   randomNum =（int）（Math.random（）*（Max  -  Min））;  
 
 time = time + 1; 
 System.out.println（Integer.toString（time）+   test）; 
 
  //  没有这2行，计时器保持正确增加 
 TextView Time =（TextView）findViewById（R.id.lblSetTime）; 
 Time.setText（Integer.toString（time））; 
 
} 
 
}; 
  final  ScheduledFuture beeperHandle = scheduler.scheduleAtFixedRate（beeper， 0 ， 1 ，SECONDS）; 
 scheduler.schedule（ new  Runnable（）{ public   void  run（）{beeperHandle.cancel（true）;}}， 60  *  60 ，SECONDS）; 
 
} 

有什么建议可以解决这个问题吗？还有关于再次点亮按钮的建议吗？我打算让一个随机数生成器点亮一个按钮，具体取决于生成的数量。



我想我也必须在取消部分上有if语句计时器，所以当生命= 0时，计时器停止并且游戏结束，尽管可以稍后查看。所以现在我只需要了解我做错了什么

解决方案

在这两行中放置一个try / catch，你会看到TextView可能没有被初始化你的应用程序的生命周期点。



那是因为函数findViewById（int）出类

活动 [ ^ ]无法返回有效值。

请阅读活动文档。

Hey guys I''m learning android by making an simple app I though up. What I''m trying to make is an simple app that every second lights up a button then a second later the light turns off, if the user hits the button while its lit up they get a point. the button which gets lit up depends on a random number generator.

I''m currently using a tutorial I found on ScheduledExecutorService to create a timer, the program outputs correctly in the console but gets stuck after updating the program once after I added the code to update a label every tick. Heres the code

private final ScheduledExecutorService scheduler =   Executors.newScheduledThreadPool(1);    
  public void beepForAnHour() 
  {
	 
	  final Runnable beeper = new Runnable() 
	  {
		 
		     public void run() 
		     { 		    	
		    			    	 
		    	// int Min = 1;
		    	// int Max = 3;
		    	// randomNum = (int) (Math.random() * ( Max - Min ));		
		    	 
		    	 time=time+1;		    	 
		    	 System.out.println(Integer.toString(time)+" test"); 

                       //without these 2 lines the timer keeps increasing correctly	
		    	 TextView Time = (TextView)findViewById(R.id.lblSetTime);
		         Time.setText(Integer.toString(time));
		    	 
		     }
		   
      };
      final ScheduledFuture beeperHandle =   scheduler.scheduleAtFixedRate(beeper, 0, 1, SECONDS);
      scheduler.schedule(new Runnable() { public void run() { beeperHandle.cancel(true); } }, 60 * 60, SECONDS);
  
  }

Any suggestions why this is a problem? And any advise on lighting the button up and off again? I planned to have a random number generator light up a button depending on the number generated.

I imagine I would also have to have if statement on the cancel part of the timer so when "lives = 0" the timer stops and the game ends although that can be looked at later. So now I just need to understand what I am doing wrong

解决方案

Put a try/catch around those 2 lines and you will see that TextView is probably not initalized at that point of your app''s life cycle.

That''s because the function findViewById(int) out of the class
Activity[^] can not return a valid value at that point.
Please read in the Documentation of Activity.

这篇关于Android Timer App问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！