在循环中使用 setInterval 来更改间隔

Question

我在这里使用第二个答案中的技术：

Changing the interval of SetInterval while it's running

但是没有设置间隔的变化。代码也使用 OpenLayers 3:

        var coordinate, 
            i = 1,
            length = multipointCoords[0].length;

        var currentTime = tracksTime[0];
        var nextTime = tracksTime[1];
        speedOption = 100; // the highter this value, the faster the tracks, see next line
        var transitionTime = (nextTime - currentTime) / speedOption;

        var timer;

        timer = setInterval(function() {
            segmentConstruction(multipointCoords, tracksTime);
        }, transitionTime);

        function segmentConstruction(multipointCoords, tracksTime) {
            coordinate = ol.proj.fromLonLat(multipointCoords[0][i]);
            lineString.appendCoordinate(coordinate);

            if (i === length - 1) {
                clearInterval(timer);
            } else {
                i++;
                map.addLayer(trackLayer);
                clearInterval(timer);
                currentTime = tracksTime[i];
                nextTime = tracksTime[i + 1];
                timer = setInterval(function() {
                    segmentConstruction(multipointCoords);
                }, transitionTime);
            };
        };

我做错了什么？

谢谢。

Answer 1

    var currentTime = tracksTime[0];
    var nextTime = tracksTime[1];
    speedOption = 100; // the highter this value, the faster the tracks, see next line
    var transitionTime = (nextTime - currentTime) / speedOption;

你在这里计算transitionTime。

        if (i === length - 1) {
            clearInterval(timer);
        } else {
            i++;
            map.addLayer(trackLayer);
            clearInterval(timer);
            currentTime = tracksTime[i];//<------------------|
            nextTime = tracksTime[i + 1];//<-----------------|
            timer = setInterval(function() {//               | 
                segmentConstruction(multipointCoords);//     |
            }, transitionTime);// <----------------------------->Not redefined
        };

这里使用和上面一样的transitionTime，没有重新定义！为什么不呢，不是错误，而是...

我不认为你的问题来自计时器，而是来自你的参数。

这里有一个片段可以看出你的代码关于时间和间隔没有问题：我刚刚删除了与 'timing' 和 interval.

无关的所有内容

var log = function(val){
    console.log(val);
    document.getElementById('el').innerHTML+='<div><pre>' + val + '</pre><div>';
  }

var timer ,
    i = 1 , 
    length = 5 ,
    transitionTime = 200 ;



        timer = setInterval(function() {
          log('first timerId : ' + timer);
          
            segmentConstruction()
        
        }, transitionTime );

        function segmentConstruction(multipointCoords, tracksTime) {
          log(' \tsegmentConstruction : i = ' + i + ' / ' + length);
        
          //if (i === length - 1) {
          if (i >= length - 1) {
                clearInterval(timer);
                log('\t\twe finish with : i = ' + i + ' / ' + length);
            } else {
                i++;
                clearInterval(timer);
                timer = setInterval(function() {
                    log('loop timerId : ' + timer);
                    segmentConstruction();
                }, transitionTime);
            };
        };

<div id='el'></div>

在循环中使用 setInterval 来更改间隔

Using setInterval in a loop to change interval

javascript

timer

setinterval

openlayers-3