CSS 彈性盒子佈局是 CSS 的模塊之一,定義了一種針對用戶界面設計而優化的 CSS 盒子模型。在彈性佈局模型中,彈性容器的子元素能夠在任何方向上排布,也能夠「彈性伸縮」其尺寸,既能夠增長尺寸以填滿未使用的空間,也能夠收縮尺寸以免父元素溢出。子元素的水平對齊和垂直對齊都能很方便的進行操控。經過嵌套這些框(水平框在垂直框內,或垂直框在水平框內)能夠在兩個維度上構建佈局。javascript
寫了一個簡單的單頁面程序,能夠在上面進行演示以查看效果,演示地址:https://codepen.io/f_zz/pen/NmPKav。css
你也能夠複製下面的代碼在本地演示:html
<!DOCTYPE html> <html> <head> <title>Flexible Box Layout show</title> <meta charset="utf-8"> <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script> <style type="text/css"> h2 { text-align: center; } .box { display: flex; width: 400px; height: 300px; border: 2px dotted #87a7bd; } .box > div{ border: 2px solid #87a7bd; border-radius: 5%; background-color: rgba(96, 139, 168, .2); } #item2{ background-color: #d4d6f3c7; } #item3{ background-color: #e0d4dcd9; } .flexBox{ display: flex; justify-content: space-around; } .left, .right{ width: 300px; } .left > *{ margin-left: 100px; } .item{ display: inline; } .item input{ width: 40px; } .boxLabel{ color: #f32d50; font-style: italic; } .itemLabel{ color: #0e67f1; font-style: italic; } #editor, #showing{ display: flex; margin-top: 30px; justify-content: center; } #showing{ margin-top: 0px; align-items: center; } #showing > p{ margin-right: 10px; font-size: 24px; } #editor > textarea{ width: 400px; height: 67px; } h2 > span{ cursor: pointer; } </style> </head> <body> <div id="app"> <h2 title="2019@fzz">Flexible Box Layout <span @click="openUrl('')">show</span></h2> <div class="flexBox"> <!--left--> <div class="left"> <!--boxStyle--> <h3>boxStyle</h3> <div v-for="(style, k) in boxStyle"> <label class="boxLabel" @click="showing(k, 'boxLabel')"> {{k}} </label> <br> <select @change="doChange($event, 'boxLabel')" :name="k"> <option v-for="op in _data[k]"> {{op}} </option> </select> </div> </div> <!--box--> <div class="box" :style="boxStyle"> <div title="doubleClicking and editing it's html" @dblclick.prevent="changeEditor" v-for="(html, id) in itemIds" :id="id" :style="_data[itemStyle[id]]" v-html="html"></div> </div> <!--left--> <div class="right"> <!--itemStyle--> <h3>itemStyle</h3> <div v-for="(style, k) in item1Style"> <label class="itemLabel" @click="showing(k, 'itemLabel')"> {{k}} </label> <br> <div v-for="(v, i) in itemStyle" class="item"> <label> {{i}} </label><input :name="k" :value="_data[_data.itemStyle[i]][k]" @keyup="doChange($event, 'itemLabel', _data.itemStyle[i])"> </div> </div> </div> </div> <!--editHtml--> <div id="editor"> <textarea @keyup="editHtml" spellcheck="false" v-model="editStr" placeholder="edit item's html from here!"></textarea> </div> <!--Description--> <div id="showing"> <p :class="currentShowingClass">{{showingP}}</p> <span>{{showingContent}}</span> </div> </div> </div> </body> <script type="text/javascript"> var app = new Vue({ el: '#app', data: { info: 'Flexible Box爲css提供的基於盒子模型的彈性佈局', boxStyle: { flexDirection: 'row', flexWrap: 'nowrap', justifyContent: 'flex-start', alignItems: 'flex-strat', alignContent: 'flex-strat', }, flexDirection: ['row', 'row-reverse', 'column', 'column-reverse'], flexWrap: ['nowrap', 'wrap', 'wrap-reverse'], justifyContent: ['flex-strat', 'flex-end', 'center', 'space-between', 'space-around'], alignItems: ['flex-strat', 'flex-end', 'center', 'baseline', 'stretch'], alignContent: ['flex-strat', 'flex-end', 'center', 'space-around', 'space-between', 'stretch'], flexFlow: ['row', 'nowrap'], itemIds: { item1: 'item1', item2: 'item2222222', item3: 'item<br>333' }, itemStyle: { item1: 'item1Style', item2: 'item2Style', item3: 'item3Style' }, item1Style: { order: 0, flexGrow: 0, flexShrink: 0, flexBasis: 'auto', alignSelf: 'auto' }, item2Style: { order: 0, flexGrow: 0, flexShrink: 0, flexBasis: 'auto', alignSelf: 'auto' }, item3Style: { order: 0, flexGrow: 0, flexShrink: 0, flexBasis: 'auto', alignSelf: 'auto' }, alignSelf: ['auto', 'flex-strat', 'flex-end', 'center', 'baseline', 'stretch'], flex: [0, 1, 'auto'], editStr: '', editorId: 'item1', currentShowingClass: '', showingP: '', showingContent: '', showings: { Flex: '是Flexible Box的縮寫,意爲」彈性佈局」,用來爲盒狀模型提供最大的靈活性。任何一個容器均可以指定爲Flex佈局。', flexDirection: '屬性決定主軸的方向(即項目的排列方向)。row(默認值):主軸爲水平方向,起點在左端。row-reverse:主軸爲水平方向,起點在右端。column:主軸爲垂直方向,起點在上沿。column-reverse:主軸爲垂直方向,起點在下沿。', flexWrap: '屬性默認狀況下,項目都排在一條線(又稱」軸線」)上。flex-wrap屬性定義,若是一條軸線排不下,如何換行。nowrap(默認):不換行。wrap:換行,第一行在上方。wrap-reverse:換行,第一行在下方。', justifyContent: '屬性定義了項目在主軸上的對齊方式。flex-start(默認值):左對齊;flex-end:右對齊;center: 居中;space-between:兩端對齊,項目之間的間隔都相等;space-around:每一個項目兩側的間隔相等。因此,項目之間的間隔比項目與邊框的間隔大一倍。', alignItems: '屬性定義項目在交叉軸上如何對齊。flex-start:交叉軸的起點對齊。flex-end:交叉軸的終點對齊。center:交叉軸的中點對齊。baseline: 項目的第一行文字的基線對齊。stretch(默認值):若是項目未設置高度或設爲auto,將佔滿整個容器的高度。', alignContent: '屬性定義了多根軸線的對齊方式。若是項目只有一根軸線,該屬性不起做用。flex-start:與交叉軸的起點對齊。flex-end:與交叉軸的終點對齊。center:與交叉軸的中點對齊。space-between:與交叉軸兩端對齊,軸線之間的間隔平均分佈。space-around:每根軸線兩側的間隔都相等。因此,軸線之間的間隔比軸線與邊框的間隔大一倍。stretch(默認值):軸線佔滿整個交叉軸。', order: '屬性定義項目的排列順序。數值越小,排列越靠前,默認爲0', flexGrow: '屬性定義項目的放大比例,默認爲0,即若是存在剩餘空間,也不放大。', flexShrink: '屬性定義了項目的縮小比例,默認爲1,即若是空間不足,該項目將縮小。負值對該屬性無效。', flexBasis: '屬性定義了在分配多餘空間以前,項目佔據的主軸空間(main size)。瀏覽器根據這個屬性,計算主軸是否有多餘空間。它的默認值爲auto,即項目的原本大小。', alignSelf: '屬性容許單個項目有與其餘項目不同的對齊方式,可覆蓋align-items屬性。默認值爲auto,表示繼承父元素的align-items屬性,若是沒有父元素,則等同於stretch。', }, }, created(){ this.showingP = 'Flex'; this.showingContent = this.showings.Flex; }, methods: { doChange: function(e, showClass, item){ var target = e.target; if(!target){ return; } var name = target.name, value = target.value; if(this.boxStyle.hasOwnProperty(name)){ this.boxStyle[name] = value; }else if(this[item] && this[item] && this[item].hasOwnProperty(name)){ this[item][name] = value; } this.showing(e.target.name, showClass); }, changeEditor: function(e){ this.editorId = e.target.id; this.editStr = this.itemIds[this.editorId]; }, editHtml: function(e){ this.itemIds[this.editorId] = this.editStr; }, showing(name, showClass){ name = name || 'Flex'; this.showingP = name; this.showingContent = this.showings[name]; this.currentShowingClass = showClass || ''; }, openUrl: function(url){ url = url || 'http://www.cnblogs.com/fzz9/'; window.open(url, '_blank') } } }); </script> </html>
https://developer.mozilla.org/zh-CN/docs/Web/CSS/CSS_Flexible_Box_Layout
http://www.runoob.com/w3cnote/flex-grammar.htmlvue