Question

我正在使用简单的jQuery幻灯片，通过使用图片标题和替代文字中的文字在图片上创建标题。它工作得很好，但我不希望它在幻灯片中的图像没有标题/ alt时显示任何内容。

请在此处查看示例代码： http://jsfiddle.net/qWZWJ/24/

我基本上需要添加一个IF语句来测试图像标题/ alt是否为空，但我不知道该怎么做。

Answer 1

将您的javascript上的“显示标题”内容更改为：

//Display the caption
if($('#slideshow-caption p').html() != "")
    $('#slideshow-caption').css({opacity: 0.7, bottom:0});

享受：）

Answer 2

嘿srry这是一个修复：

将此作为您的脚本使用：

<script type="text/javascript">
$(document).ready(function() {        

    //Execute the slideShow, set 4 seconds for each images
    slideShow(2000);

});

var timer;

function slideShow(speed) {


    //append a LI item to the UL list for displaying caption
    $('ul.slideshow').append('<li id="slideshow-caption" class="caption"><div class="slideshow-caption-container"><h3></h3><p></p></div></li>');

    //Set the opacity of all images to 0
    $('ul.slideshow li').css({opacity: 0.0});

    //Get the first image and display it (set it to full opacity)
    $('ul.slideshow li:first').css({opacity: 1.0}).addClass('show');

    //Get the caption of the first image from REL attribute and display it
    $('#slideshow-caption h3').html($('ul.slideshow li.show').find('img').attr('title'));
    $('#slideshow-caption p').html($('ul.slideshow li.show').find('img').attr('alt'));

    //Call the gallery function to run the slideshow    
    timer = setInterval('gallery()',speed);

    //pause the slideshow on mouse over
    $('ul.slideshow').hover(
        function () {
            clearInterval(timer);    
        },     
        function () {
            timer = setInterval('gallery()',speed);            
        }
    );

}

function gallery() {


    //if no IMGs have the show class, grab the first image
    var current = ($('ul.slideshow li.show')?  $('ul.slideshow li.show') : $('#ul.slideshow li:first'));

    //trying to avoid speed issue
    if(current.queue('fx').length == 0) {    

        //Get next image, if it reached the end of the slideshow, rotate it back to the first image
        var next = ((current.next().length) ? ((current.next().attr('id') == 'slideshow-caption')? clearInterval(timer) :current.next()) : $('ul.slideshow li:first'));

        if (next) {    

            //Get next image caption
            var title = next.find('img').attr('title');    
            var desc = next.find('img').attr('alt');    

            //Set the fade in effect for the next image, show class has higher z-index
            next.css({opacity: 0.0}).addClass('show').animate({opacity: 1.0}, 1000);

            //Hide the caption first, and then set and display the caption
            $('#slideshow-caption').slideToggle(300, function () {
                $('#slideshow-caption h3').html(title);
                $('#slideshow-caption p').html(desc);
                if(desc != "" || title != "")
                {
                    $('#slideshow-caption').css({opacity: 0.7, bottom:0});   
                    $('#slideshow-caption').slideToggle(500);                                         
                }
            });        

            //Hide the current image
            current.animate({opacity: 0.0}, 1000).removeClass('show');
        }
    }

}
</script>

如果alt文本为空，则禁止幻灯片显示标题

2 个答案: