[Organization and Sharing] Essential operating skills for Vue development, come and collect them!

• In js we usually bind an event to get the code of the key, and then pass ## in event #keyCode Attribute to get the code
If we need to implement a fixed key to trigger the event, we need to constantly judge, which is actually very troublesome

let button = document.querySelector('button')

button.onkeyup = function (e) {
    console.log(e.key)
    if (e.keyCode == 13) {
        console.log('我是回车键')
    }
}

• vue provides aliases for some commonly used keys. We only need to add the response alias after the event.
• vue Common aliases are: up/ Up arrow, down/down arrow, left/left arrow, right/right arrow, space/space, tab/line feed, esc/exit, enter/carriage return, delete/delete

// 只有按下回车键时才会执行 send 方法
<input v-on:keyup.enter="send" type="text">

For keys that do not provide aliases in
• Vue, you can use the original key value to bind. The so-called key value is event.key Obtained value
If the
• key value is a single letter, you can use it directly. If it is a camel case name consisting of multiple words, you need to split it and use - Connection

// 只有按下q键时才会执行send方法
<input v-on:keyup.Q="send" type="text">

// 只有按下capslock键时才会执行send方法
<input v-on:keyup.caps-lock="send" type="text">

For system modifiers
• ctrl, alt, shift these comparisons For the use of complex keys, there are two situations
Because these keys can be pressed while pressing other keys to form a combination shortcut key
• When the trigger event is
• keydown , we can directly press the modifier to trigger
When the trigger event is
• keyup, when pressing the modifier key, press other keys at the same time, and then release other keys , the event can be triggered.

// keydown事件时按下alt键时就会执行send方法
<input v-on:keydown.Alt="send" type="text">

// keyup事件时需要同时按下组合键才会执行send方法
<input v-on:keyup.Alt.y="send" type="text">

Of course we can also customize the key alias
• through
• Vue.config.keyCodes. Custom key name = key code Define

// 只有按下回车键时才会执行send方法
<input v-on:keydown.autofelix="send" type="text">
    
// 13是回车键的键码，将他的别名定义为autofelix
Vue.config.keyCodes.autofelix=13

We often need to use picture preview in projects,
• viewerjs is a very cool picture preview Plug-in
Function support includes image enlargement, reduction, rotation, dragging, switching, stretching, etc.
• Installation
• viewerjsExtension

npm install viewerjs --save

Introduce and configure the function

//引入
import Vue from 'vue';
import 'viewerjs/dist/viewer.css';
import Viewer from 'v-viewer';

//按需引入
Vue.use(Viewer);

Viewer.setDefaults({
    'inline': true,
    'button': true, //右上角按钮
    "navbar": true, //底部缩略图
    "title": true, //当前图片标题
    "toolbar": true, //底部工具栏
    "tooltip": true, //显示缩放百分比
    "movable": true, //是否可以移动
    "zoomable": true, //是否可以缩放
    "rotatable": true, //是否可旋转
    "scalable": true, //是否可翻转
    "transition": true, //使用 CSS3 过度
    "fullscreen": true, //播放时是否全屏
    "keyboard": true, //是否支持键盘
    "url": "data-source",
    ready: function (e) {
        console.log(e.type, '组件以初始化');
    },
    show: function (e) {
        console.log(e.type, '图片显示开始');
    },
    shown: function (e) {
        console.log(e.type, '图片显示结束');
    },
    hide: function (e) {
        console.log(e.type, '图片隐藏完成');
    },
    hidden: function (e) {
        console.log(e.type, '图片隐藏结束');
    },
    view: function (e) {
        console.log(e.type, '视图开始');
    },
    viewed: function (e) {
        console.log(e.type, '视图结束');
        // 索引为 1 的图片旋转20度
        if (e.detail.index === 1) {
            this.viewer.rotate(20);
        }
    },
    zoom: function (e) {
        console.log(e.type, '图片缩放开始');
    },
    zoomed: function (e) {
        console.log(e.type, '图片缩放结束');
    }
})

Use the picture preview plug-in
• Use a single picture

<template>
  <div>
    <viewer>
      <img :src="cover" style="cursor: pointer;" height="80px">
    </viewer>
  </div>
</template>
 
<script>
export default {
  data() {
    return {
      cover: "//www.autofelix.com/images/cover.png"
    }
  }
}
</script>

Use multiple pictures

<template>
  <div>
    <viewer :images="imgList">
      <img v-for="(imgSrc, index) in imgList" :key="index" :src="imgSrc" />
    </viewer>
  </div>
</template>
 
<script>
export default {
  data() {
    return {
      imgList: [
        "//www.autofelix.com/images/pic_1.png",
        "//www.autofelix.com/images/pic_2.png",
        "//www.autofelix.com/images/pic_3.png",
        "//www.autofelix.com/images/pic_4.png",
        "//www.autofelix.com/images/pic_5.png"
      ]
    }
  }
}
</script>

This is a fun special effects technique
• For example, when you pick up people at the airport, you can use the marquee special effects on your mobile phone. Become the most handsome boy in the crowd
• The marquee special effect is actually to delete the first text and add it to the last one, thus forming the effect of text movement

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>跑马灯</title>
    <style type="text/css">
        #app {
            padding: 20px;
        }
    </style>
</head>

<body>
    <div id="app">
        <button @click="run">应援</button>
        <button @click="stop">暂停</button>
        <h3>{{ msg }}</h3>
    </div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue@2.7.0/dist/vue.min.js"></script>
<script>
    new Vue({
        el: "#app",
        data: {
            msg: "飞兔小哥，飞兔小哥，我爱飞兔小哥~~~",
            timer: null // 定时器
        },
        methods: {
            run() {
                // 如果timer已经赋值就返回
                if (this.timer) return;

                this.timer = setInterval(() => {
                    // msg分割为数组
                    var arr = this.msg.split('');
                    // shift删除并返回删除的那个，push添加到最后
                    // 把数组第一个元素放入到最后面
                    arr.push(arr.shift());
                    // arr.join('')吧数组连接为字符串复制给msg
                    this.msg = arr.join('');
                }, 100)
            },
            stop() {
                //清除定时器
                clearInterval(this.timer);
                //清除定时器之后，需要重新将定时器置为null
                this.timer = null;
            }
        }
    })
</script>

</html>

There are many applications for the countdown technique
• For example, when there are many rush-buying products, we need to have a countdown to remind users of the time to start the rush
• In fact, it is every other Seconds, recalculate the time and assign it to
• DOM

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>倒计时</title>
</head>

<body>
    <div id="app">
        <div>抢购开始时间：{{count}}</div>
    </div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue@2.7.0/dist/vue.min.js"></script>
<script>
    new Vue({
        el: "#app",
        data() {
            return {
                count: '', //倒计时
                seconds: 864000 // 10天的秒数
            }
        },
        mounted() {
            this.Time() //调用定时器
        },
        methods: {
            // 天 时 分 秒 格式化函数
            countDown() {
                let d = parseInt(this.seconds / (24 * 60 * 60))
                d = d < 10 ? "0" + d : d
                let h = parseInt(this.seconds / (60 * 60) % 24);
                h = h < 10 ? "0" + h : h
                let m = parseInt(this.seconds / 60 % 60);
                m = m < 10 ? "0" + m : m
                let s = parseInt(this.seconds % 60);
                s = s < 10 ? "0" + s : s
                this.count = d + &#39;天&#39; + h + &#39;时&#39; + m + &#39;分&#39; + s + &#39;秒&#39;
            },
            //定时器没过1秒参数减1
            Time() {
                setInterval(() => {
                    this.seconds -= 1
                    this.countDown()
                }, 1000)
            },
        }
    })
</script>

</html>

In the project, we sometimes You need to customize the options that appear with the right mouse button instead of the browser's default right-click options
• How to implement the right-click menu is actually very simple in
• Vue, just use vue-contextmenujs Plug-in can be installed
• vue-contextmenujs Plug-in

npm install vue-contextmenujs

Introduction

//引入
import Vue from 'vue';
import Contextmenu from "vue-contextmenujs"

Vue.use(Contextmenu);

How to use
• You can use
• You can add icons to options
You can use
• style Style of label customization option
You can use
• disabled You can click the attribute to disable the option
You can use
• divided:true Set the underline of the option
You can use
• children to set sub-options

<style>
    .custom-class .menu_item__available:hover,
    .custom-class .menu_item_expand {
        background: lightblue !important;
        color: #e65a65 !important;
    }
</style>


<template>
    <div style="width:100vw;height:100vh" @contextmenu.prevent="onContextmenu"></div>
</template>

<script>
    import Vue from 'vue'
    import Contextmenu from "vue-contextmenujs"
    Vue.use(Contextmenu);

    export default {
        methods: {
            onContextmenu(event) {
                this.$contextmenu({
                    items: [
                        {
                            label: "返回",
                            onClick: () => {
                                // 添加点击事件后的自定义逻辑
                            }
                        },
                        { label: "前进", disabled: true },
                        { label: "重载", divided: true, icon: "el-icon-refresh" },
                        { label: "打印", icon: "el-icon-printer" },
                        {
                            label: "翻译",
                            divided: true,
                            minWidth: 0,
                            children: [{ label: "翻译成中文" }, { label: "翻译成英文" }]
                        },
                        {
                            label: "截图",
                            minWidth: 0,
                            children: [
                                {
                                    label: "截取部分",
                                    onClick: () => {
                                        // 添加点击事件后的自定义逻辑
                                    }
                                },
                                { label: "截取全屏" }
                            ]
                        }
                    ],
                    event, // 鼠标事件信息
                    customClass: "custom-class", // 自定义菜单 class
                    zIndex: 3, // 菜单样式 z-index
                    minWidth: 230 // 主菜单最小宽度
                });
                return false;
            }
        }
    };
</script>

Supports printing function for web pages, which is also common in many projects
• To use the printing function in Vue, you can use the
• vue-print-nb plug-in
installation
• vue-print-nb plug-in

npm install vue-print-nb --save

Introducing printing service

import Vue from 'vue'
import Print from 'vue-print-nb'
Vue.use(Print);

Use
• Use the
• v-print command to start the printing function

<div id="printStart">
    <p>红酥手，黄縢酒，满城春色宫墙柳。</p>
    <p>东风恶，欢情薄。</p>
    <p>一怀愁绪，几年离索。</p>
    <p>错、错、错。</p>
    <p>春如旧，人空瘦，泪痕红浥鲛绡透。</p>
    <p>桃花落，闲池阁。</p>
    <p>山盟虽在，锦书难托。</p>
    <p>莫、莫、莫！</p>
</div>
<button v-print="&#39;#printStart&#39;">打印</button>

• jsonp is one of the main ways to solve cross-domain issues
So learn how to It is actually very important to use
• jsonp in vue
Installation
• jsonpExtension

npm install vue-jsonp --save-dev

Registration Service

// 在vue2中注册服务
import Vue from 'vue'
import VueJsonp from 'vue-jsonp'
Vue.use(VueJsonp)

// 在vue3中注册服务
import { createApp } from 'vue'
import App from './App.vue'
import VueJsonp from 'vue-jsonp'
createApp(App).use(VueJsonp).mount('#app')

Usage method
• It should be noted that after using
• jsonp to request data, the callback is not then Instead of executing
in the custom
• callbackName, it needs to be mounted on the window object

<script>
export default {
  data() {...},
  created() {
    this.getUserInfo()
  },
  mounted() {
    window.jsonpCallback = (data) => {
        // 返回后回调
        console.log(data)
    }
  },
  methods: {
    getUserInfo() {
     this.$jsonp(this.url, {
      callbackQuery: "callbackParam",
      callbackName: "jsonpCallback"
     })
      .then((json) => {
          // 返回的jsonp数据不会放这里，而是在 window.jsonpCallback
          console.log(json)
      })  
    }
  }
 }
</script>