Question

我写了一些代码，当我将鼠标悬停在某个元素上时，会在其周围添加四个箭头并循环播放动画，以便它们前后移动。

这是为了直观地显示该元素是可拖动的。我正在使用hoverIntent插件仅在用户想要将鼠标悬停在元素上时绘制箭头。我也在使用jQueryUI进行元素定位。

将一个项目附加到文档然后设置动画是我以前从未做过的事情，我确信我编写的这个项目效果不佳导致性能低于最佳状态。

我怎样才能使这段代码表现更好？

jQuery.fx.interval = 1;

// Add Hover arrows
$('.table-row.songnamecolumn').livequery(function($songRow) {
    var $songRow = $(this).closest('tr').children('td');
    var $appenditem = $(this);
    var $this = $(this);

    var loop = function loop(){
        $('#toparrow').animate({ top:'-=15px'},500).animate({ top:'+=15px'},100);
        $('#bottomarrow').animate({ top:'+=15px'},500).animate({ top:'-=15px'},100);
        $('#leftarrow').animate({ left:'-=15px'},500).animate({ left:'+=15px'},100);
        $('#rightarrow').animate({ left:'+=15px'},500).animate({ left:'-=15px'},100);
    }

    $(this).hoverIntent({
        sensitivity: 3, // How sensitive the hoverIntent should be
        interval: 200, // How often in milliseconds the onmouseover should be checked
        over: slidedrag, // Function to call when mouseover is called    
        timeout: 200, // How often in milliseconds the onmouseout should be checked
        out: slidedragback // Function to call when mouseout is called    
    }); 

    function slidedrag() {  
        $('<div id="toparrow"></div>'
        +'<div id="leftarrow"></div>'
        +'<div id="rightarrow"></div>'
        +'<div id="bottomarrow"></div>').appendTo($appenditem);

        $('#toparrow').position ({
            of: $this,
            my: 'center top',
            at: 'center top',
            offset: "0 -18"
        })

        $('#bottomarrow').position ({
            of: $(this),
            my: 'center bottom',
            at: 'center bottom',
            offset: "0 18"
        })

        $('#leftarrow').position ({
            of: $(this),
            my: 'left center',
            at: 'left center',
            offset: "-10 0"
        })

        $('#rightarrow').position ({
            of: $(this),
            my: 'right center',
            at: 'right center',
            offset: "10 0"
        })

        $('#toparrow, #bottomarrow, #leftarrow, #rightarrow').animate({opacity:'0.5'},600);
        setInterval(loop, 600);
    }

    function slidedragback() {
        clearInterval(loop);
        $('#toparrow, #bottomarrow, #leftarrow, #rightarrow').animate({opacity:'0'},600);
        $('#toparrow,#bottomarrow,#leftarrow,#rightarrow').remove();
    }
});

Answer 1

我看到你不止一次选择相同的元素。我建议你将它们存储为局部变量并调用变量：

var arrow_top = $('#toparrow');

删除代码块中的空格：

out: slidedragback // Function to call when mouseout is called    
}); 



function slidedrag() {

最后，避免做过动画。

如何提高此jquery动画代码的性能

1 个答案: