这里的逻辑有什么问题

What's wrong with the logic here?

本文关键字:什么 问题 这里      更新时间:2023-09-26

我目前正在使用Google Maps V3 API,我正在为一个标记制作动画,以沿着预定的路线行驶。路线信息存储在两个单独的数组中,lat用于纬度坐标,lon用于经度坐标。我在尝试构建按钮以暂停和恢复标记的移动时遇到逻辑问题。这是代码:

  var paused = 0; //paused state
  var interval = 1000; //interval for animation (ms)
  function clickPause() {
      paused = 1;
  }
  function clickPlay() {
      paused = 0;
  }
  function moveToStep(yourmarker,yourroute,c) {
      var LatLon;
      var time;
      var hours;
      var minutes;
      var seconds;
      var finalTime;
      var stopTime;
      if (yourroute.length > c) {
          LatLon = new google.maps.LatLng(lat[c],lon[c]);
          yourmarker.setPosition(LatLon);
          document.getElementById("currlat").innerHTML = lat[c];
          document.getElementById("currlon").innerHTML = lon[c];
          document.getElementById("currtime").innerHTML = c+1;
          hours = 7+Math.floor((c+1)/3600);
          minutes = Math.floor((c+1)/60);
          seconds = (c+1)-minutes*60;
          if(minutes == 60) {
              minutes = 0;
          }
          finalTime = str_pad_left(hours,'0',2)+':'+str_pad_left(minutes,'0',2)+':'+str_pad_left(seconds,'0',2);
          document.getElementById("finaltime").innerHTML = finalTime;
          if(paused == 1) {
              stopTime = c+1;
              window.setInterval(function(){
                  if(paused == 0) {
                      moveToStep(yourmarker,yourroute,stopTime);
                  }
              },interval);
          }
          else {
              window.setTimeout(function(){
                  moveToStep(yourmarker,yourroute,c+1);
              },interval);
          }
      }
  }
  function str_pad_left(string,pad,length) {
      return (new Array(length+1).join(pad)+string).slice(-length); 
  }
  function jumpTo(value) {
      alert(value);
      moveToStep(marker,lat,100);
  }
  function initialize() {
    var mapOptions = {
      center: new google.maps.LatLng(31.26,121.45),
      zoom: 12,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    var map = new google.maps.Map(document.getElementById("map_canvas"),
        mapOptions);
    var marker = new google.maps.Marker({map: map,});
    var newLatLng = new google.maps.LatLng(lat[0],lon[0]);
    marker.setPosition(newLatLng);
    moveToStep(marker,lat,0);
  }

现在,我有两个按钮,一个调用clickPause()函数,另一个调用clickPlay()函数。暂停工作正常,但是当我尝试恢复时,标记表现出一些非常奇怪的行为。

从本质上讲,标记似乎跳回到上次暂停的位置,然后再次快速向前跳跃,并在每次标记位置更新时执行此操作(每 1000 毫秒一次,或每秒一次,由 interval 变量设置)。

以前有人见过这种行为吗?我不明白我的逻辑在这些行中有什么问题,我敢肯定这是罪魁祸首:

          if(paused == 1) {
              stopTime = c+1;
              window.setInterval(function(){
                  if(paused == 0) {
                      moveToStep(yourmarker,yourroute,stopTime);
                  }
              },interval);
          }
          else {
              window.setTimeout(function(){
                  moveToStep(yourmarker,yourroute,c+1);
              },interval);
          }

我所做的只是检查模拟是否暂停,如果是,请检查它是否已取消暂停,然后一旦暂停,恢复标记的移动。一旦我按下恢复按钮,代码应该直接转到

              window.setTimeout(function(){
                  moveToStep(yourmarker,yourroute,c+1);
              },interval);

因为paused的值已返回给1

谁能帮我?

您需要清除间隔,以便在恢复后阻止它触发。这意味着您需要存储 setInterval 返回的标识符,并在需要时将其传递给clearInterval

var pauseInterval; // interval identifier (outside the moveToStep function)
if (paused == 1) {
    stopTime = c+1;
    pauseInterval = setInterval(function() {
        if(paused == 0) {
            moveToStep(yourmarker, yourroute, stopTime);
        }
    }, interval);
} else {
    clearInterval(pauseInterval);
    setTimeout(function() {
        moveToStep(yourmarker, yourroute, c+1);
    }, interval);
}