按钮单击更改Java语言中的图像

时间:2018-08-25 07:02:04

标签: javascript html css arrays image

我仍在学习Javacript。这是我在家中的第一个任务。但是,即使我尝试按照说明逐步进行操作,我似乎也无法使代码正常工作。我需要创建一个幻灯片,当我单击该按钮时,将出现一个新图像,直到循环回到第一个图像为止。我检查了所有内容,但仍然无法弄清楚自己做错了什么。如果您能解释和帮助,我将不胜感激。

<body onload="startup();">
    <center>

    <img id="banner" src="images/bangkok_thailand.jpg"> 
    <br>
    <button onclick="cycle();">Click Here to Change Image</button>

<script>
        var imgArray = new Array();
        var index = 0;


function cycle() {
            document.getElementById("banner").src = imgArray[index].src;
            index = index + 1;
            if (index > 5 ) {
                index = 0;
            }
            return;

}

function startup()
    {
        imgArray[0] = new Image;
        imgArray[1] = new Image;
        imgArray[2] = new Image;
        imgArray[3] = new Image; 
        imgArray[4] = new Image; 
        imgArray[5] = new Image;

    imgArray[0]. src="images/bangkok_thailand.jpg";
    imgArray[1]. src="images/paris_france.jpg";
    imgArray[2]. src="images/seoul_southkorea.jpg";
    imgArray[3]. src="images/tokyo_japan.jpg";
    imgArray[4]. src="images/istanbul_turkey.jpg";
    imgArray[5]. src="images/amsterdam_netherlands";
    }
    //cycle();
    return;


</script>
</center>

1 个答案:

答案 0 :(得分:1)

首先,您在脚本上有一个流浪return-这导致该函数无法加载。其次,在imgArray[x].src之间有一个空格。解决第一个问题,它应该可以工作,第二个问题是可选的,但您也要修复它。

我在下面的演示中使用https://picsum.photos/。希望这会有所帮助

<body onload="startup();">
  <center>

    <img id="banner" src="https://picsum.photos/400/300/?random">
    <br>
    <button onclick="cycle();">Click Here to Change Image</button>
    <script>
      var imgArray = new Array();
      var index = 0;


      function cycle() {
        document.getElementById("banner").src = imgArray[index].src;
        index = index + 1;
        if (index > 5) {
          index = 0;
        }
        return;
      }

      function startup() {
        imgArray[0] = new Image;
        imgArray[1] = new Image;
        imgArray[2] = new Image;
        imgArray[3] = new Image;
        imgArray[4] = new Image;
        imgArray[5] = new Image;

        imgArray[0].src = "https://picsum.photos/350/300/?random";
        imgArray[1].src = "https://picsum.photos/300/300/?random";
        imgArray[2].src = "https://picsum.photos/250/300/?random";
        imgArray[3].src = "https://picsum.photos/200/300/?random";
        imgArray[4].src = "https://picsum.photos/150/300/?random";
        imgArray[5].src = "https://picsum.photos/100/300/?random";
      }
    </script>
  </center>
</body>