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Related usage of css_position_html/css_WEB-ITnose
- WBOYOriginal
- 2016-06-24 11:38:54899browse
Introduction
position is used to fix the position and is a particularly important attribute
The value can be:
1 <style type="text/css"> 2 div 3 { 4 position:100px 100px; 5 width:100px; 6 height:100px; 7 border:5px solid black; 8 } 9 div.pos_left10 {11 position:relative;12 left:-20px;13 border:5px solid green;14 }15 div.pos_right16 {17 position:relative;18 left:20px;19 border:5px solid green;20 }21 div.pos_ab22 {23 position:absolute;24 left:30px;25 top:50px;26 border:5px solid blue;27 }28 div.main29 {30 position:absolute;31 left:100px;32 top:50px;33 width:200px;34 height:300px;35 border:5px solid red;36 }37 div.pos_fix38 {39 position:fixed;40 left:10px;41 top:0px;42 clip:rect(0px 50px 200px 0px);43 }44 </style>45 </head>46 47 <body>48 <div class="main">49 <div>1.normal</div>50 <div class="pos_left">2.re-left:-20px</div>51 <div class="pos_right">3.re-left:20px</div>52 <div class="pos_ab">4.ab-(left:30px,top:50px)</div>53 <div class="pos_right">5.re-left:20px</div>54 <div class="pos_fix">6.fix-(left:30px,top:50px)</div>55 </div> Among them:
When setting position: relative
, refer to the parent middle-top The upper left corner of the content area of a child element is positioned using the original point combined with the TRBL attribute. If there is no parent, the upper left corner of the BODY is used as the original point
?? It must be noted that the upper left corner relative to the previous child element is not the upper left corner shown in the 2 to 3 picture. In other words, if [2] is static, the upper left corner will not be TRBL transformed.
??That is, even if the relative element is TRBL transformed, the interval it occupies is still the original interval, so it will cover other elements.
More obvious display:
Change [2] in the picture:
position: relative;
left:-20px;
top:-50px;
Then:
An area in the figure that contains the blank areas above and below [2] and [3] is [ 2】Really occupied space
. When setting position: relative
, refer to the upper left corner of the parent The corner is positioned as the original point combined with the TRBL attribute. If there is no parent, the upper left corner of the browser is the original point
At the same time, we can see from the relative attribute [5]?? [5] is relative to the space of [3]
?? Absolute is equivalent to directly covered without possessing real space
When setting the position: related The upper left corner is the original point
In addition