Question

很抱歉提出这个问题。我对Java比较陌生。我在构建倒数计时器方面获得了帮助，但突然之间它以二分之一运行。我可能做错了什么？我想我缺少一个微小的细节，但我找不到。请怎么了。

    $("#coinbtn1").click(function() {
      var fiveMinutes = 60 * 5,
        display = document.querySelector('#time1');
      startTimer1(fiveMinutes, display);
    });
    
    function startTimer1(duration, display) {
      var timer = duration,
        minutes, seconds;
        
      var intervalFn = function() {
    	  
        minutes = parseInt(timer / 60, 10)
        seconds = parseInt(timer % 60, 10);
    
        minutes = minutes < 10 ? "0" + minutes : minutes;
        seconds = seconds < 10 ? "0" + seconds : seconds;
    
        display.textContent = minutes + ":" + seconds;
    	
    	if(--timer != 0){
    		document.getElementById('coinbtn1').disabled = true;
    	}
    	
    	if (--timer === 0) {
    		  clearInterval(myVar);
    		  document.getElementById('coinbtn1').disabled = false;
    		}
        
      };
      
      myVar = setInterval(intervalFn, 1000);
      
      intervalFn();
      

    }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="mdl-card__actions mdl-card--border">
    						<div>Timer : <span  id="time1">05:00</span></div>
                                <div class="mdl-grid">
    							
    							<div class="mdl-layout-spacer"></div>
    							
                                    <button id="coinbtn1" class="mdl-button mdl-js-button mdl-js-ripple-effect mdl-button--raised mdl-button--colored">
    							50 coins 
    							</button>
    							<div class="mdl-layout-spacer"></div>
                                </div>
    							
                            </div>

请帮助。

Answer 1

问题是您有两个if语句在其条件下使用--timer。

--timer将导致timer减小，而不论if条件是否为true（--是"decrement" operator）。

相反，只需检查timer-1（这不会导致timer被修改），然后在这两个测试之后仅手动减少一次计时器。

$("#coinbtn1").click(function() {
  var fiveMinutes = 60 * 5,
  display = document.querySelector('#time1');
  startTimer1(fiveMinutes, display);
});
    
function startTimer1(duration, display) {
  var timer = duration, minutes, seconds;
  var intervalFn = function() {
    	  
    minutes = parseInt(timer / 60, 10)
    seconds = parseInt(timer % 60, 10);
    
    minutes = minutes < 10 ? "0" + minutes : minutes;
    seconds = seconds < 10 ? "0" + seconds : seconds;
    
    display.textContent = minutes + ":" + seconds;
    	
    // Don't decrease the timer in the test
    if(timer-1 != 0){
      document.getElementById('coinbtn1').disabled = true;
    }
    	
    // Don't decrease the timer in the test      
    if (timer-1 === 0) {
      clearInterval(myVar);
      document.getElementById('coinbtn1').disabled = false;
    }
  
    --timer; // Decrease the counter just once.
  }
 
  myVar = setInterval(intervalFn, 900);
      
  intervalFn();
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="mdl-card__actions mdl-card--border">
  <div>Timer : <span  id="time1">05:00</span></div>
  <div class="mdl-grid">						
    <div class="mdl-layout-spacer"></div>					
    <button id="coinbtn1" class="mdl-button mdl-js-button mdl-js-ripple-effect mdl-button--raised mdl-button--colored">50 coins</button>
    <div class="mdl-layout-spacer"></div>
  </div>
</div>

Answer 2

您要在

中将

f = new File(tmpdir, fn);

递减2次

timer

使用if-else代替if(--timer != 0){ document.getElementById('coinbtn1').disabled = true; } if (--timer === 0) { clearInterval(myVar); document.getElementById('coinbtn1').disabled = false; }两次，并在最后一次减少计时器。这样。

if

计时器无法正常运行-Javascript

2 个答案: