vue2練習五個小例子筆記
多練習,多擼程式碼,多進步.
1.雙向資料繫結
<!--vue例項上繫結click事件hideTooltip-->
<div id="main" @click="hideTooltip">
<!--v-if判斷show_tooltip,為true則顯示,並且繫結了一個阻止單擊事件冒泡-->
<div class="tooltip" v-if="show_tooltip" @click.stop>
<!--用v-modal繫結了text_content,能夠雙向更新資料-->
<input type="text" v-model="text_content" />
</div>
<!--因為雙向繫結的關係,所以這裡可以一邊輸入,一邊輸出內容-->
<p @click.stop="toggleTooltip">{{text_content}}</p>
</div>-
.stop這種用法是vue的一種語法糖,名叫事件修飾符,這裡的是阻止單擊事件冒泡 -
@這種也是一種vue的語法糖,名叫縮寫,繫結事件的縮寫
var demo = new Vue({
el: `#main`,
data: {
show_tooltip: false, //給v-if判斷使用的布林值
text_content: `Edit me.`
},
methods: {
//click繫結的事件
hideTooltip: function() {
this.show_tooltip = false; //this可以呼叫當前vue例項的內容,也就是說this指向當前vue例項的作用域
},
//true/false的切換,他們的切換會直接硬性v-if的判斷,從而實現隱藏和出現的效果
toggleTooltip: function() {
this.show_tooltip = !this.show_tooltip;
}
}
});2.導航切換
<div id="main">
<nav @click.prevent>
<!--v-for遍歷輸出內容,並且繫結了class-->
<!-- <a v-for="item in items" :class="{`show`: item.active}" @click="makeActive(item, $index)">{{item.name}}</a>-->
<!--之前寫法有問題,沒檢查好,css無法切換-->
<a v-for="(item,index) in items" :class="{`show`: item.active}" @click="makeActive(item,index)">
{{item.name}}
</a>
</nav>
<p>You chose <b>{{active}}</b></p>
</div>-
.prevent阻止預設事件,這裡主要是為了阻止a標籤的點選自動跳轉或者重新整理頁面的預設事件 -
:是vue的縮寫,v-bind的縮寫 -
show 的更新將取決於資料屬性 item.active 是否為真值,參考繫結class
-
makeActive(item, index)這個是最主要的,控制item的active屬性-
v-for是通過一個物件的屬性來迭代的,items的key就是0123,value就是item物件,所以轉換一下方便看,將key和vaule轉為item和idnex
-
var vm = new Vue({
el:`#main`,
data:{
active:`HTML`,
items:[ //被遍歷的陣列
{name:`HTML`, active:true}, //通過控制active的值(布林值)來做一些處理,例如為true的時候show,為false的hide
{name:`CSS`, active:false},
{name:`JavaScript`, active:false},
{name:`Vue.js`, active:false}
]
},
methods: {
makeActive: function(item, index){ //使用傳入的當前的v-for迴圈的遍歷項和當前索引
this.active = item.name;
for(var i=0; i<this.items.length;i++){//將所有item設定為false
this.items[i].active = false;
}
this.items[index].active = true;//然後單獨設定選中的item為true
}
}
});參考demo
3.即時搜尋
<div id="main">
<div class="bar">
<!--v-modal的雙向繫結-->
<input type="text" v-model="searchStr" placeholder="Enter your search terms"/>
</div>
<ul>
<!--這裡使用了articles1來做特別標誌,證明這個計算屬性不是在data裡面的,而是通過計算出來的-->
<!--通過遍歷計算屬性articles1來輸出需要的資訊-->
<li v-for="a in articles1">
<a :href="a.url"><img :src="a.image"/></a>
<p>{{a.title}}</p>
</li>
</ul>
</div> new Vue({
el: `#main`,
data: {
searchStr: "", //雙向繫結的屬性
articles: [
{
"title": "What You Need To Know About CSS Variables",
"url": "http://tutorialzine.com/2016/03/what-you-need-to-know-about-css-variables/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2016/03/css-variables-100x100.jpg"
},
{
"title": "Freebie: 4 Great Looking Pricing Tables",
"url": "http://tutorialzine.com/2016/02/freebie-4-great-looking-pricing-tables/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/great-looking-pricing-tables-100x100.jpg"
},
{
"title": "20 Interesting JavaScript and CSS Libraries for February 2016",
"url": "http://tutorialzine.com/2016/02/20-interesting-javascript-and-css-libraries-for-february-2016/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/interesting-resources-february-100x100.jpg"
},
{
"title": "Quick Tip: The Easiest Way To Make Responsive Headers",
"url": "http://tutorialzine.com/2016/02/quick-tip-easiest-way-to-make-responsive-headers/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/quick-tip-responsive-headers-100x100.png"
},
{
"title": "Learn SQL In 20 Minutes",
"url": "http://tutorialzine.com/2016/01/learn-sql-in-20-minutes/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2016/01/learn-sql-20-minutes-100x100.png"
},
{
"title": "Creating Your First Desktop App With HTML, JS and Electron",
"url": "http://tutorialzine.com/2015/12/creating-your-first-desktop-app-with-html-js-and-electron/",
"image": "http://cdn.tutorialzine.com/wp-content/uploads/2015/12/creating-your-first-desktop-app-with-electron-100x100.png"
}
]
},
computed: { //使用計算屬性
articles1: function () { //這個articles1就是計算屬性
if(!this.searchStr){ //沒有輸入搜尋項就不處理
return false;
}
var s = this.searchStr.trim().toLowerCase();
//使用js的filter遍歷迴圈,通過在這裡處理迴圈之後然後返回處理好的陣列給v-for進行處理
var result = this.articles.filter(function (item) {
if (item.title.toLowerCase().indexOf(s) !== -1) {
return item;
}
});
return result;
}
}
});demo例子使用vue1,然後jsfiddle已經升級了vue2了,vue2拋棄了大部分過濾器,所以無法執行(vue2的過濾器升級),在這裡我稍微修改了一下,使用vue2寫法來實現
4.佈局切換
<div id="main">
<div class="bar">
<!--v-bind繫結class的用法,並且通過click改變layout屬性-->
<a class="grid-icon" v-bind:class="{ `active`: layout == `grid`}" v-on:click="layout = `grid`"></a>
<a class="list-icon" v-bind:class="{ `active`: layout == `list`}" v-on:click="layout = `list`"></a>
</div>
<!--v-if判斷layout屬性的變化來切換顯示-->
<ul v-if="layout == `grid`" class="grid">
<li v-for="a in articles">
<a v-bind:href="a.url" target="_blank"><img v-bind:src="a.image.large" /></a>
</li>
</ul>
<ul v-if="layout == `list`" class="list">
<li v-for="a in articles">
<a v-bind:href="a.url" target="_blank"><img v-bind:src="a.image.small" /></a>
<p>{{a.title}}</p>
</li>
</ul>
</div> /*bar的icon用了base64的圖*/
.bar a.list-icon{
background-image:url(data:image/png;base64,iVBORw0KGgXXXXXX);
}
.bar a.grid-icon{
background-image:url(data:image/png;base64,iVBORw0XXXXXXX);
}
/*grid和list兩種佈局的css都寫好了,只要相對切換.gird或者.list就可以實現變化*/
ul.grid{
width: 570px;
margin: 0 auto;
text-align: left;
}
ul.grid li{
padding: 2px;
float:left;
}
ul.grid li img{
width:280px;
height:280px;
object-fit: cover;
display:block;
border:none;
}
ul.list{
width: 500px;
margin: 0 auto;
text-align: left;
}
ul.list li{
border-bottom: 1px solid #ddd;
padding: 10px;
overflow: hidden;
}
ul.list li img{
width:120px;
height:120px;
float:left;
border:none;
}
ul.list li p{
margin-left: 135px;
font-weight: bold;
color:#6e7a7f;
} var demo = new Vue({
el: `#main`,
data: {
layout: `grid`,
articles: [{
"title": "What You Need To Know About CSS Variables",
"url": "http://tutorialzine.com/2016/03/what-you-need-to-know-about-css-variables/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2016/03/css-variables.jpg",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2016/03/css-variables-150x150.jpg"
}
},
{
"title": "Freebie: 4 Great Looking Pricing Tables",
"url": "http://tutorialzine.com/2016/02/freebie-4-great-looking-pricing-tables/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/great-looking-pricing-tables.jpg",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/great-looking-pricing-tables-150x150.jpg"
}
},
{
"title": "20 Interesting JavaScript and CSS Libraries for February 2016",
"url": "http://tutorialzine.com/2016/02/20-interesting-javascript-and-css-libraries-for-february-2016/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/interesting-resources-february.jpg",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/interesting-resources-february-150x150.jpg"
}
},
{
"title": "Quick Tip: The Easiest Way To Make Responsive Headers",
"url": "http://tutorialzine.com/2016/02/quick-tip-easiest-way-to-make-responsive-headers/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/quick-tip-responsive-headers.png",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2016/02/quick-tip-responsive-headers-150x150.png"
}
},
{
"title": "Learn SQL In 20 Minutes",
"url": "http://tutorialzine.com/2016/01/learn-sql-in-20-minutes/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2016/01/learn-sql-20-minutes.png",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2016/01/learn-sql-20-minutes-150x150.png"
}
},
{
"title": "Creating Your First Desktop App With HTML, JS and Electron",
"url": "http://tutorialzine.com/2015/12/creating-your-first-desktop-app-with-html-js-and-electron/",
"image": {
"large": "http://cdn.tutorialzine.com/wp-content/uploads/2015/12/creating-your-first-desktop-app-with-electron.png",
"small": "http://cdn.tutorialzine.com/wp-content/uploads/2015/12/creating-your-first-desktop-app-with-electron-150x150.png"
}
}]
}
});5.合計總價
<div id="main" v-cloak>
<h1>Services</h1>
<ul>
<!--v-for遍歷,繫結click監聽,切換active-->
<!--將currency filter的寫法更換為toFixed-->
<li v-for="item in items" @click="toggleActive(item)" :class="{`active`:item.active}">{{item.name}}<span>{{item.price.toFixed(2)}}</span></li>
</ul>
<!--這裡注意的是直接使用vue的方法的寫法-->
<p>Total: <span>{{total()}}</span></p>
</div>依然修改了vue2的filter的使用
var demo = new Vue({
el: `#main`,
data: {
items: [
{
name: `Web Development`,
price: 300,
active:false
},{
name: `Design`,
price: 400,
active:false
},{
name: `Integration`,
price: 250,
active:false
},{
name: `Training`,
price: 220,
active:false
}
]
},
methods: {
toggleActive: function(i){
i.active = !i.active; //簡單的寫法切換true/false
},
total: function(){
var total = 0;
this.items.forEach(function(s){ //用js的forEach遍歷陣列
if (s.active){ //只要判斷active才會處理計算
total+= s.price;
}
});
return total.toFixed(2);//將currency filter的寫法更換
}
}
});