• 西游之路——python全栈——瀑布流


     ###############################

    class Picture(models.Model):
        src = models.ImageField(verbose_name='图片路径', upload_to='./static/images/picture/')
        title = models.CharField(verbose_name='标题', max_length=32)
        summary = models.CharField(verbose_name='简介', max_length=32)
    
        class Meta:
            verbose_name_plural = '图片'
    
        def __str__(self):
            return self.title
    Models.py Code

     ##############################

     1 def picture(request):
     2     picture_list = models.Picture.objects.all()
     3     return render(request, 'picture.html', locals())
     4 
     5 def get_img(request):
     6     nid = request.GET.get('nid')
     7     picture_list = models.Picture.objects.filter(id__gt=nid).values('id','title','src')
     8     # print(picture_list)  # <QuerySet [{'k1':v1,'k1:v2'},{'k1':v3,'k1:v4'}]>
     9     picture_list = list(picture_list)
    10     # print(picture_list)   # [{'k1':v1,'k1:v2'},{'k1':v3,'k1:v4'}]
    11     ret = {'status':True,'data':None}
    12     ret['data'] = picture_list
    13 
    14     return HttpResponse(json.dumps(ret))
    View.py Code

     #############################

     1 <!DOCTYPE html>
     2 <html lang="en">
     3 <head>
     4     <meta charset="UTF-8">
     5     <title>Title</title>
     6     <style>
     7         .w{
     8             width: 1000px;
     9             margin: 0 auto;
    10         }
    11         .item{
    12             width: 25%;
    13             float: left;
    14         }
    15         .item img{
    16             width: 100%;
    17         }
    18     </style>
    19 </head>
    20 <body>
    21         <div>姑娘们</div>
    22         <div class="w" id="container">
    23             <div class="item">11</div>
    24             <div class="item">22</div>
    25             <div class="item">33</div>
    26             <div class="item">44</div>
    27         </div>
    28 
    29         <script src="/static/js/jquery.js"></script>
    30         <script>
    31             $(function() {
    32                 var obj = new ScrollImg();
    33                 obj.initImg();
    34                 obj.scrollEvent();
    35             });
    36             function ScrollImg() {
    37                 this.NID = 0;
    38                 //赋值-1或展示列数减1,解决第一次展示时第一个位置对应第一张图片
    39                 this.lastPosition = -1;
    40                 this.initImg = function initImg() {
    41                     //**************this = obj*************
    42                     var that = this;
    43                     $.ajax({
    44                         url: '/get_img.html',
    45                         type: 'GET',
    46                         data: {nid:this.NID},
    47                         dataType: 'JSON',
    48                         success:function(arg) {
    49                             var img_list = arg.data;
    50                             $.each(img_list,function (index,v) {
    51                                 //index为从零开始的序号,v为循环出来的对象
    52                                 //console.log(index,v);
    53                                 //加cont+1为了使下次下次展示的图片能接上
    54                                 var eqv = (index+that.lastPosition+1) % 4;
    55                                 console.log(eqv);
    56                                 var tag = document.createElement('img');
    57                                 tag.src = '/' + v.src;
    58                                 //$('#container').children().eq(eqv)先找到container下children与eqv匹配的序号
    59                                 //然后再append插入img标签,这里需要创建tag
    60                                 $('#container').children().eq(eqv).append(tag);
    61                                 //判断循环结束,并记录结束时ID和eqv
    62                                 if(index+1 == img_list.length) {
    63                                     //为什么不加var?
    64                                     that.lastPosition = eqv;
    65                                     //that.NID = v.id;
    66                                 }
    67                             });
    68                         }
    69                     });
    70                 };
    71                 this.scrollEvent = function scrollEvent() {
    72                     //this = obj
    73                     var that = this;
    74                     //当滚轮到达最底部时,执行initImg()
    75                     $(window).scroll(function() {
    76                         //什么时候到达最底部?
    77                         //文档高度
    78                         var docHeight = $(document).height();
    79                         //窗口高度
    80                         var winHeight = $(window).height();
    81                         //滚动条可滚动高度
    82                         var scrollTop = $(window).scrollTop();
    83                         var scrollTop = Math.round(scrollTop);
    84                         //检查监听情况
    85                         //console.log(docHeight,winHeight,scrollTop);
    86                         if(winHeight+scrollTop == docHeight) {
    87                             //console.log(1);
    88                             that.initImg();
    89                         }
    90                     });
    91                 };
    92             }
    93         </script>
    94 
    95 </body>
    96 </html>
    HTML Code
    注意:避免定义全局变量,需用对象进行封装

    要点:

      - 布局
      - 文档、窗口、滚动
      - 面向对象的封装:this,that

  • 相关阅读:
    python学习笔记3:python读写文件
    python学习笔记3:字典
    python学习笔记3:列表、元组和集合
    python学习笔记2:字符串
    Linux之DNS
    网络安全
    linux之防火墙
    Linux之进程管理命令
    Linux之进程管理基础
    Linux之网络
  • 原文地址:https://www.cnblogs.com/Lujun1028/p/9646000.html
Copyright © 2020-2023  润新知