jquery - 如果替代文本为空白，则禁止显示幻灯片标题

Question

我正在使用一个简单的 jQuery 幻灯片，它通过使用图像标题和替代文本中的文本在图像上创建标题。它很好用，但是当幻灯片中的图像没有标题/替代时，我不希望它显示任何内容。

请参阅此处的示例代码：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 是否为空白，但我不知道该怎么做。

Answer 1

将 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});

请享用 ：）

Answer 2

嘿，对不起，这是一个修复：

使用它作为你的脚本：

<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>