这里的绑定其实就是v-bind的绑定,如代码所示,div后面的引号就是v-bind绑定,然后大括号将整个对象括起来,对象内先是属性,属性后接的是变量,这个变量是定义在script中的,后通过这个变量,来控制属性,实现绑定。
先设置个盒子,并为其设置style样式,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box"></view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(false)
const Size = ref(30) ;
let i = 0 ; //这个值不在模板层渲染,可以不用ref
setInterval(()=>{
i++ ;
Size.value += i ;
isactive.value = !isactive.value
picurl.value = arrs.value[i%4] ;
},1000)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
效果如下:
再添加一个类名,为其设置样式,也就是说,用两个类名作用于同一个盒子。继续在盒子中添加文字,设置字体大小,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box active">v-bind指令</view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(false)
const Size = ref(30) ;
let i = 0 ; //这个值不在模板层渲染,可以不用ref
setInterval(()=>{
i++ ;
Size.value += i ;
isactive.value = !isactive.value
picurl.value = arrs.value[i%4] ;
},1000)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
效果如下:
如图所示,现在实现了两个类名共同作用于一个类名,且在两个类名定义相同属性的情况下,下方的样式会优先作用于类。
现在,尝试把active变成动态的值,先删掉之前定义的active,现在用v-bind形式定义active,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "'active'">v-bind指令</view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(false)
const Size = ref(30) ;
let i = 0 ; //这个值不在模板层渲染,可以不用ref
setInterval(()=>{
i++ ;
Size.value += i ;
isactive.value = !isactive.value
picurl.value = arrs.value[i%4] ;
},1000)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
这里的显示效果和刚刚的效果相同。这里请注意定义active时的格式,尤其是在使用动态绑定,要加上一个单引号,以表示它是字符串类型的类名,否则没法作用上的。
接下来,尝试用一个值来控制active,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:true}">v-bind指令</view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(false)
const Size = ref(30) ;
let i = 0 ; //这个值不在模板层渲染,可以不用ref
setInterval(()=>{
i++ ;
Size.value += i ;
isactive.value = !isactive.value
picurl.value = arrs.value[i%4] ;
},1000)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
如开头所说的,这里用大括号将整个对象括起来,对象内包含了属性active,属性后接的是变量,可以写上true或者false,以控制active,这里我们用的是true,效果如下:
还可以将这个变量定义在script中,后通过这个变量,来控制属性,实现绑定,这里我们定义变量为false,记住一定要用ref来定义,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:isactive}">v-bind指令</view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(false)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
效果如下:
这是一种方法, 日常使用中,还可以使用三元表达式来控制active,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "true?'active' : ' ' ">v-bind指令</view>
</template>
<script setup>
import { ref } from 'vue';
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(true)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
当然,三元表达式的判断条件也可以填入刚刚设置的isactive变量。
接下来,把变量放入定时器,让其动态改变,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:isactive}">v-bind指令</view>
<view calss="box" :class = "isactive?'active':'box'"></view>
</template>
<script setup>
import { ref } from 'vue';
setInterval(()=>{
isactive.value = !isactive.value
},1000)
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(true)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
width: 200px;
height: 200px;
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
成功:
以上两种都是常用的方式,接下来演示一下内联的样式,先写个简单的内联样式,设置第二个box的宽度,要注意的是,内联样式的权重更高,会覆盖其他样式,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:isactive}">v-bind指令</view>
<!-- <view calss="box" :class = "isactive?'active':'box'"></view> -->
<view class="box" style = "width: 300px;">内联样式</view>
</template>
<script setup>
import { ref } from 'vue';
setInterval(()=>{
isactive.value = !isactive.value
},1000)
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(true)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
width: 200px;
height: 200px;
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
效果如下:
如果要使用变量,就需要在style的前面加上冒号,并以对象的形式定义,刚刚定义了宽度,要用单引号括起来,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:isactive}">v-bind指令</view>
<!-- <view calss="box" :class = "isactive?'active':'box'"></view> -->
<view class="box" :style = "{width:'300px'}">内联样式</view>
</template>
<script setup>
import { ref } from 'vue';
setInterval(()=>{
isactive.value = !isactive.value
},1000)
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(true)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
width: 200px;
height: 200px;
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
或者用数字+‘单位’(例:260 + ‘px’ )这样的形式写出,也是可以的。
通过内联,也可以实现动态变量,将字体大小定义为数字 + ‘单位’的形式,然后用变量替换掉数字,并将其放入定时器中,代码如下:
<template>
<view>
<view><image :src="picurl"></image></view>
</view>
<button :loading="false">按钮!</button>
<view class="box" :class = "{active:isactive}">v-bind指令</view>
<!-- <view calss="box" :class = "isactive?'active':'box'"></view> -->
<view class="box" :style = "{width:'300px',height:260 + 'px',fontSize:fontsize + 'px'}">内联样式</view>
</template>
<script setup>
import { ref } from 'vue';
let i = 0 ;
let fontsize = ref(30) ;
setInterval(()=>{
isactive.value = !isactive.value
i ++ ;
fontsize.value += i ;
},1000)
const arrs = ref(
["../../static/pic1.png",
"../../static/pic2.png",
"../../static/pic3.webp",
"../../static/pic4.jpg"]
) ;
const picurl = ref("../../static/pic1.png") ;
const isactive = ref(true)
</script>
<style lang="scss">
.box{
width: 200px;
height: 200px;
background: orange;
font-size: 20px;
}
.active{
width: 200px;
height: 200px;
background: green; //下面的CSS可以覆盖上面的
color: white;
}
</style>
效果如下: