Question

我是javascript和jquery的新手。我想在加载页面时加载随机图像。我发现一些代码看起来很简单，但我似乎无法使它工作，我不知道我做错了什么。一切看起来都很好....

我的HTML如下：

<html xmlns="http://www.23.org/19999/xhtml">
<head>
    <title>A  Site Just For Me!</title>
    <script type="text/javascript" src="jquery.min.js"></script>
    <link href='http://fonts.googleapis.com/css?family=Economica:400,700|Francois+One' rel='stylesheet' type='text/css'>

    <script type="text/javascript" src="myjs.js"></script> 
    <!-- Latest compiled and minified CSS -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css">

    <!-- Optional theme -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap-theme.min.css">

    <!-- Latest compiled and minified JavaScript -->
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>

    <link rel="stylesheet" type="text/css" href="me_css.css">

</head>

<body >         
    <div class="jumbotron">
        <div class="container">
            <div class="greeting"></div>
            <div id="happypic"></div>
            <div id="banner"></div>
            <div id="banner2"></div>
        </div>
    </div>
</body>
</html>

这是我的javascript文件：

// A $( document ).ready() block.
$( document ).ready(function() {

});

//This is where i set up my greeting.

var nowDate=new Date();
var nowHour=nowDate.getHours();
var greeting;

if (nowHour<11)
{
    //good morning
    greeting="Good morning";
}   
else if (nowHour<16)
     {
        //good afternoon
        greeting="Good afternoon";
     }
     else 
     {
        //good evening
        greeting="Good evening";
     }
//document.write("<center><h1>"+greeting+", Loser!");//

// This is where i put my random picture chooser
// pictures

//random image experiment

var hawaiiPix=new Array("hawaii1.jpg", "hawaii2.jpg", "hawaii3.jpg", "hawaii4.jpg", "hawaii5.jpg");
$('<img src="img/'+hawaiiPix[Math.floor(Math.random()*hawaiiPix.length)]+'">"').appendTo('#happypic');

var images = ["hawaii1.jpg", "hawaii2.jpg", "hawaii3.jpg", "hawaii4.jpg", "hawaii5.jpg"];
$('<img src="images/' + images[Math.floor(Math.random() * images.length)] + '">').appendTo('#banner');

$('<h1>Hello</h1>').appendTo('#banner2');

非常感谢任何见解......

Answer 1

问题是你的jQuery代码在 ready函数之外，所以它在加载DOM之前运行，因此无法添加图像，因为HTML中不存在这些元素页面还没有。

一种方法是将myjs.js文件加载到</body>之前，这样当它执行时，项目被加载（你需要删除jQuery.ready代码）或者你可以把它放到在就绪块内部，如下所示：

$( document ).ready(function() {
 //This is where i set up my greeting.
    var nowDate=new Date();
    var nowHour=nowDate.getHours();
    var greeting;

    if (nowHour<11)
    {
        //good morning
        greeting="Good morning";
    }   

    else if (nowHour<16)
    {
        //good afternoon
        greeting="Good afternoon";
    }
    else 
    {
        //good evening
        greeting="Good evening";
    }
    //document.write("<center><h1>"+greeting+", Loser!");//

    // This is where i put my random picture chooser
    // pictures

    //random image experiment

    var hawaiiPix=new Array("hawaii1.jpg", "hawaii2.jpg", "hawaii3.jpg", "hawaii4.jpg", "hawaii5.jpg");
    $('<img src="img/'+hawaiiPix[Math.floor(Math.random()*hawaiiPix.length)]+'">"').appendTo('#happypic');

    var images = ["hawaii1.jpg", "hawaii2.jpg", "hawaii3.jpg", "hawaii4.jpg", "hawaii5.jpg"];
    $('<img src="images/' + images[Math.floor(Math.random() * images.length)] + '">').appendTo('#banner');


    $('<h1>Hello</h1>').appendTo('#banner2');
});

最好的方法是在html代码的底部移动jQuery和JS文件的加载。

尝试使用jquery加载随机图像 - 不工作

1 个答案: