快速做一个js打赏弹窗小功能，比较简单，不复杂，放着以后随手就调用一下……

放在前端页面喜欢的位置上，点击一下就会弹出的位置

<button type="button" id="ClickMe"> <i class="icon iconfont icon-yulebao"></i> <span>打赏</span> </button>

html代码

<div id="goodcover"></div>
<div id="code">
<div class="close1"><a href="javascript:void(0)" id="closebt"><img src="<?php $this->options->themeUrl('img/close.gif'); ?>"></a></div>
<div class="goodtxt">
打赏内容
</div>
<div class="code-img"></div>
</div>

这里是样式美化，也可以自己修改调整

#goodcover {
    display: none;
    position: fixed;
    top: 0%;
    left: 0%;
    width: 100%;
    height: 133%;
    background-color: #000;
    z-index: 1001;
    -moz-opacity: .8;
    opacity: .7;
    filter: alpha(opacity=80)
}

#code {
    padding: 10px;
    background-size: cover;
    background-repeat: no-repeat;
    background-position: 50% 50%;
    background-color: #313435;
    z-index: 1002;
    border-radius: 8px;
        display: none;
}

.close1 {    
    position: relative;
}

.close1 i{
    font-size: 25px;
    font-weight: 700;
    color: white;
    position: absolute;
        right: -20px;
    top: -30px;

}
.goodtxt {
    margin-left: 30px; 
}
.goodtxt p {
    font-size: 16px;
    color: #fff;    
}
.goodtxt .vtip{ font-size: 12px; color: #b3b3b3;}
.code-img {
    width: 250px;
    padding: 10px
}
.code-img img {
    width: 240px
}

js代码：

$(function() {
    //alert($(window).height());
    $('#ClickMe').click(function() {
        $('#code').center();
        $('#goodcover').show();
        $('#code').fadeIn();
    });
    $('#closebt').click(function() {
        $('#code').hide();
        $('#goodcover').hide();
    });
    $('#goodcover').click(function() {
        $('#code').hide();
        $('#goodcover').hide();
    });
    /*var val=$(window).height();
    var codeheight=$("#code").height();
    var topheight=(val-codeheight)/2;
    $('#code').css('top',topheight);*/
    jQuery.fn.center = function(loaded) {
        var obj = this;
        body_width = parseInt($(window).width());
        body_height = parseInt($(window).height());
        block_width = parseInt(obj.width());
        block_height = parseInt(obj.height());

        left_position = parseInt((body_width / 2) - (block_width / 2) + $(window).scrollLeft());
        if (body_width < block_width) {
            left_position = 0 + $(window).scrollLeft();
        };

        top_position = parseInt((body_height / 2) - (block_height / 2) + $(window).scrollTop());
        if (body_height < block_height) {
            top_position = 0 + $(window).scrollTop();
        };

        if (!loaded) {

            obj.css({
                'position': 'fixed'
            });
            obj.css({
                'top': ($(window).height() - $('#code').height()) * 0.5,
                'left': left_position
            });
            $(window).bind('resize', function() {
                obj.center(!loaded);
            });
            $(window).bind('scroll', function() {
                obj.center(!loaded);
            });

        } else {
            obj.stop();
            obj.css({
                'position': 'absolute'
            });
            obj.animate({
                'top': top_position
            }, 200, 'linear');
        }
    }
})

还有其他的更好的吧，但是个人觉得这个也不错……