Question

嗨，我正在制作一个涉及倒数计时器的游戏。我希望在单击计时器按钮时启动游戏，但此时我的计时器才会自行启动。我已经看过几个已经回答的不同问题但是它们对我没有用。有什么建议吗？

     var seconds = 60;
     function secondPassed() {
        var minutes = Math.round((seconds - 30)/60);
        var remainingSeconds = seconds % 60;
        if (remainingSeconds < 10) {
           remainingSeconds = "0" + remainingSeconds;  
        }
        document.getElementById('countdown').innerHTML = minutes + ":" + remainingSeconds;
        if (seconds == 0) {
          clearInterval(countdownTimer);
          document.getElementById('countdown').innerHTML = "Times Up!!!";
        } else {
           seconds--;
        }
     }

     var countdownTimer = setInterval('secondPassed()', 1000);

Answer 1

我猜你在点击按钮时调用countdownTimer，如果是这样，你必须在函数中包装setInterval。

var countdownTimer = setInterval('secondPassed()', 1000); //Without the wrapper it simply executes, when JS reaches this line

应该是

var countdownTimer = function(){setInterval('secondPassed()', 1000);}

Answer 2

将setInterval添加到按钮的单击侦听器：

var btn = document.getElementById('BUTTON_ID');
btn.addEventListener('click', function() {
    setInterval('secondPassed()', 1000);
});

jsfiddle DEMO

定时开始按钮

2 个答案: