<!-- <div> <textarea type="text" v-model="text" placeholder="请输入...."></textarea> <p>输入的内容是:</p> <p style="white-space:pre">{{text}}</p> </div>这段代码的变量是什么,怎么定义
时间: 2023-08-14 22:06:52 浏览: 49
这段代码中定义了两个变量:`text`和`message`。
在Vue中,可以使用`ref`函数来定义响应式变量。`ref`函数会返回一个带有`.value`属性的响应式对象。在模板中,可以使用`v-model`指令将变量与输入框进行双向绑定。
下面是对代码进行修改后的示例:
```html
<template>
<div>
<textarea v-model="text" placeholder="请输入...."></textarea>
<p>输入的内容是:</p>
<p style="white-space: pre">{{ text }}</p>
</div>
</template>
<script setup>
import { ref } from 'vue'
let text = ref('') // 定义text变量,并初始化为空字符串
</script>
```
在上面的示例中,我们使用`ref`函数定义了一个名为`text`的变量,并初始化为空字符串。然后,在模板中使用`v-model`指令将这个变量与文本框进行双向绑定。当用户在文本框中输入内容时,`text`变量的值会自动更新,并在页面上显示出来。
相关问题
<main-content :ifDetail="true"> <div class="two-side"> <div class="main-left"> <el-form :model="form" :rules="rules" ref="form" label-width="120px"> <el-form-item label="选择下载模块" prop="accountName"> <el-input v-model.trim="form.accountName" :maxlength="50"></el-input> </el-form-item> <el-form-item label="倾斜度"> <el-slider v-model.number="form.rotate" :min="-180" :max="180"></el-slider> </el-form-item> <el-form-item label="文字"> <el-input type="textarea" v-model="form.text"></el-input> </el-form-item> <el-form-item label="文字大小"> <el-input-number v-model.number="form.fontSize" :min="10" :max="50"></el-input-number> px </el-form-item> <el-form-item label="位置"> <el-select placeholder="请选择位置" v-model="form.alignment"> <el-option v-for="item in options" :key="item.value" :label="item.label" :value="item.value"></el-option> </el-select> </el-form-item> <el-form-item> <el-select v-if="form.alignment === 2" placeholder="请选择位置" v-model="form.textPosition"> <el-option v-for="item in textPositionOptions" :key="item.value" :label="item.label" :value="item.value" ></el-option> </el-select> </el-form-item> </el-form> {{ watermarkStyle }} </div> <div class="main-right" id="show"> <div class="watermark"> <span :style="watermarkStyle" ref="showText" style="word-break:break-all;display: inline-block">{{ form.text }}</span> </div> </div> </div> </main-content> 左边来控制右边div里水印展示,代码怎么写
您可以在 `<el-form>` 标签上绑定 `@input` 事件,当表单数据发生改变时,触发该事件,然后在事件处理函数中计算出水印的样式,并将样式绑定到 `<span>` 标签上。具体实现代码如下:
```
<template>
<main-content :ifDetail="true">
<div class="two-side">
<div class="main-left">
<el-form :model="form" :rules="rules" ref="form" label-width="120px" @input="handleInput">
<!-- 表单项省略 -->
</el-form>
</div>
<div class="main-right" id="show">
<div class="watermark">
<span :style="watermarkStyle" ref="showText" style="word-break:break-all;display: inline-block">{{ form.text }}</span>
</div>
</div>
</div>
</main-content>
</template>
<script>
export default {
data() {
return {
form: {
accountName: '',
rotate: 0,
text: '',
fontSize: 16,
alignment: 1,
textPosition: 1
},
options: [
{ label: '左上', value: 1 },
{ label: '居中', value: 2 },
{ label: '右下', value: 3 }
],
textPositionOptions: [
{ label: '正常', value: 1 },
{ label: '斜体', value: 2 }
]
}
},
computed: {
watermarkStyle() {
const { rotate, fontSize, alignment, textPosition } = this.form
const deg = rotate + (textPosition === 2 ? -45 : 0)
const translateX =
alignment === 1 ? '-10%' : alignment === 2 ? '-50%' : '90%'
const translateY =
alignment === 1 ? '-10%' : alignment === 2 ? '-50%' : '90%'
const transform = `rotate(${deg}deg)`
const style = {
position: 'absolute',
top: 0,
left: 0,
bottom: 0,
right: 0,
fontSize: `${fontSize}px`,
transform: transform,
'-webkit-transform': transform,
'-ms-transform': transform,
'-moz-transform': transform,
'-o-transform': transform,
opacity: '0.2',
'pointer-events': 'none',
'text-align': 'center',
'z-index': 9999,
transformOrigin: '50% 50%',
'-webkit-transform-origin': '50% 50%',
'-ms-transform-origin': '50% 50%',
'-moz-transform-origin': '50% 50%',
'-o-transform-origin': '50% 50%',
color: '#000',
'word-break': 'break-all',
'white-space': 'pre-wrap',
'max-height': '100%',
'max-width': '100%',
overflow: 'hidden',
'text-overflow': 'ellipsis',
'-webkit-text-fill-color': 'transparent',
'-webkit-background-clip': 'text',
'background-clip': 'text',
'-webkit-user-select': 'none',
'-moz-user-select': 'none',
'-ms-user-select': 'none',
userSelect: 'none',
'-webkit-line-clamp': '1',
display: 'flex',
'align-items': 'center',
'justify-content': 'center',
'transform-style': 'preserve-3d'
}
if (textPosition === 2) {
style.padding = '0.5rem'
style.background =
'linear-gradient(to right bottom, rgba(255, 255, 255, 0.2) 0%, rgba(255, 255, 255, 0.2) 45%, rgba(255, 255, 255, 0) 50%, rgba(255, 255, 255, 0.2) 55%, rgba(255, 255, 255, 0.2) 100%)'
}
style.transform += ` translate(${translateX}, ${translateY})`
style['-webkit-transform'] += ` translate(${translateX}, ${translateY})`
style['-moz-transform'] += ` translate(${translateX}, ${translateY})`
style['-ms-transform'] += ` translate(${translateX}, ${translateY})`
style['-o-transform'] += ` translate(${translateX}, ${translateY})`
return style
}
},
methods: {
handleInput() {
this.$nextTick(() => {
const { width, height } = this.$refs.show.getBoundingClientRect()
const { offsetWidth, offsetHeight } = this.$refs.showText
if (width === 0 || height === 0 || offsetWidth === 0 || offsetHeight === 0) {
return
}
const scaleX = width / offsetWidth
const scaleY = height / offsetHeight
const scale = Math.min(scaleX, scaleY)
this.$refs.showText.style.transform += `scale(${scale})`
this.$refs.showText.style['-webkit-transform'] += `scale(${scale})`
this.$refs.showText.style['-moz-transform'] += `scale(${scale})`
this.$refs.showText.style['-ms-transform'] += `scale(${scale})`
this.$refs.showText.style['-o-transform'] += `scale(${scale})`
})
}
}
}
</script>
```
代码中的 `watermarkStyle` 计算属性用于计算水印的样式,`handleInput` 方法用于在计算出水印样式后,将水印按照比例缩小并居中显示。注意,为了保证水印样式的正确性,需要在表单项加载完成之后计算水印样式,因此需要在 `handleInput` 方法中使用 `$nextTick` 方法等待表单项加载完成再进行计算。
<el-form-item label="事故形态" pop="xingtai"> <el-select v-model="form.xingtai" @change="chaxingtai(form.xingtai)" placeholder="请选择事故形态" size="small" > <el-option label="碰撞" value="碰撞"></el-option> <el-option label="刮蹭" value="刮蹭"></el-option> <el-option label="碾压" value="碾压"></el-option> <el-option label="翻车" value="翻车"></el-option> <el-option label="坠车" value="坠车"></el-option> <el-option label="失火" value="失火"></el-option> <el-option label="撞固定物" value="撞固定物"></el-option> <el-option label="撞静止车辆" value="撞静止车辆"></el-option> <el-option label="其他" value="其他" ></el-option> </el-select> <div v-if="xingtaiqita" style="width: 200px"> <el-input type="textarea" v-model="form.select_1" size="small" clearable > ></el-input > </div> </el-form-item>以上代码写出表单验证
你可以使用element-ui提供的表单验证来验证该字段是否为空。示例代码如下:
```
<template>
<el-form :model="form" :rules="rules" ref="form">
<el-form-item label="事故形态" prop="xingtai" pop="xingtai">
<el-select
v-model="form.xingtai"
@change="chaxingtai(form.xingtai)"
placeholder="请选择事故形态"
size="small"
>
<el-option label="碰撞" value="碰撞"></el-option>
<el-option label="刮蹭" value="刮蹭"></el-option>
<el-option label="碾压" value="碾压"></el-option>
<el-option label="翻车" value="翻车"></el-option>
<el-option label="坠车" value="坠车"></el-option>
<el-option label="失火" value="失火"></el-option>
<el-option label="撞固定物" value="撞固定物"></el-option>
<el-option label="撞静止车辆" value="撞静止车辆"></el-option>
<el-option label="其他" value="其他"></el-option>
</el-select>
<div v-if="xingtaiqita" style="width: 200px">
<el-input
type="textarea"
v-model="form.select_1"
size="small"
clearable
></el-input>
</div>
</el-form-item>
<el-form-item>
<el-button type="primary" @click="submitForm">提交</el-button>
</el-form-item>
</el-form>
</template>
<script>
export default {
data() {
return {
form: {
xingtai: '',
select_1: ''
},
xingtaiqita: false,
rules: {
xingtai: [
{
required: true,
message: '请选择事故形态',
trigger: 'change'
}
]
}
}
},
methods: {
chaxingtai(value) {
if (value === '其他') {
this.xingtaiqita = true
} else {
this.xingtaiqita = false
}
},
submitForm() {
this.$refs.form.validate(valid => {
if (valid) {
// 表单验证通过,提交表单
console.log('submit')
} else {
// 表单验证失败
console.log('error submit')
return false
}
})
}
}
}
</script>
```
在上面的代码中,我们给`el-form-item`组件设置了`prop`属性为`xingtai`,这是为了在验证时使用。在`rules`中,我们设置了`xingtai`字段必填,如果该字段为空,则会提示用户选择事故形态。在`submitForm`方法中,我们调用了`this.$refs.form.validate()`方法来进行表单验证,如果验证成功,则可以提交表单,否则会提示用户错误信息。