Vue學習

    小鹹兒又來給大家分享新知識了。最近小鹹兒在做前端是Vue的項目，初步接觸之下，感覺這是一個很有意思的框架，看起來十分的簡單。

    首先來看一下Vue是什麼？

    在介紹Vue是什麼之前，來看一下從哪裏瞭解Vue呢？

    一是百度百科，百度一下Vue是什麼？

    百度介紹：Vue.js是一個構建數據驅動的web界面的漸進式框架。Vue.js的目標是通過儘可能簡單的API實現響應的數據綁定和組合的視圖組件。

    說完百度的介紹了，接下來從官網介紹來認識一下它：

    那麼二就是Vue官網：Vue.js

    從官網首頁中就可以看出Vue是漸進式JavaScript框架，易用、靈活和高效。而且Vue還有一個好處就是中文社區文檔都比較齊全，想要尋找什麼功能組件都可以輕易的找到。瞭解發展史和該如何搭建都有一套模板，方便實用。

    三是小鹹兒使用的是iview：https://www.iviewui.com

    這個文檔十分強大，而且學習起來十分方面，組件也很全面，在新手實踐方面起到了強大的引導功能。

    在通過這三個方面的學習就對於Vue有了不少的瞭解了。接下來就是了解一下在編寫代碼的頁面中它的佈局：

    這裏就相當於HTML頁面，編寫頁面顯示的代碼

<template>
    <div class="demo-upload-list" v-for="item in uploadList">
        <template v-if="item.status === 'finished'">
            <img :src="item.url">
            <div class="demo-upload-list-cover">
                <Icon type="ios-eye-outline" @click.native="handleView(item.name)"></Icon>
                <Icon type="ios-trash-outline" @click.native="handleRemove(item)"></Icon>
            </div>
        </template>
        <template v-else>
            <Progress v-if="item.showProgress" :percent="item.percentage" hide-info></Progress>
        </template>
    </div>
    <Upload
        ref="upload"
        :show-upload-list="false"
        :default-file-list="defaultList"
        :on-success="handleSuccess"
        :format="['jpg','jpeg','png']"
        :max-size="2048"
        :on-format-error="handleFormatError"
        :on-exceeded-size="handleMaxSize"
        :before-upload="handleBeforeUpload"
        multiple
        type="drag"
        action="//jsonplaceholder.typicode.com/posts/"
        style="display: inline-block;width:58px;">
        <div style="width: 58px;height:58px;line-height: 58px;">
            <Icon type="ios-camera" size="20"></Icon>
        </div>
    </Upload>
    <Modal title="View Image" v-model="visible">
        <img :src="'https://o5wwk8baw.qnssl.com/' + imgName + '/large'" v-if="visible" style="width: 100%">
    </Modal>
</template>

    這裏則是寫方法的地方，相當於js頁面

<script>
    export default {
        data () {
            return {
                defaultList: [
                    {
                        'name': 'a42bdcc1178e62b4694c830f028db5c0',
                        'url': 'https://o5wwk8baw.qnssl.com/a42bdcc1178e62b4694c830f028db5c0/avatar'
                    },
                    {
                        'name': 'bc7521e033abdd1e92222d733590f104',
                        'url': 'https://o5wwk8baw.qnssl.com/bc7521e033abdd1e92222d733590f104/avatar'
                    }
                ],
                imgName: '',
                visible: false,
                uploadList: []
            }
        },
        methods: {
            handleView (name) {
                this.imgName = name;
                this.visible = true;
            },
            handleRemove (file) {
                const fileList = this.$refs.upload.fileList;
                this.$refs.upload.fileList.splice(fileList.indexOf(file), 1);
            },
            handleSuccess (res, file) {
                file.url = 'https://o5wwk8baw.qnssl.com/7eb99afb9d5f317c912f08b5212fd69a/avatar';
                file.name = '7eb99afb9d5f317c912f08b5212fd69a';
            },
            handleFormatError (file) {
                this.$Notice.warning({
                    title: 'The file format is incorrect',
                    desc: 'File format of ' + file.name + ' is incorrect, please select jpg or png.'
                });
            },
            handleMaxSize (file) {
                this.$Notice.warning({
                    title: 'Exceeding file size limit',
                    desc: 'File  ' + file.name + ' is too large, no more than 2M.'
                });
            },
            handleBeforeUpload () {
                const check = this.uploadList.length < 5;
                if (!check) {
                    this.$Notice.warning({
                        title: 'Up to five pictures can be uploaded.'
                    });
                }
                return check;
            }
        },
        mounted () {
            this.uploadList = this.$refs.upload.fileList;
        }
    }
</script>

    最後style這裏，聽名字也能想到這裏就是調試頁面樣式的地方了，就相當於CSS頁面。

<style>
    .demo-upload-list{
        display: inline-block;
        width: 60px;
        height: 60px;
        text-align: center;
        line-height: 60px;
        border: 1px solid transparent;
        border-radius: 4px;
        overflow: hidden;
        background: #fff;
        position: relative;
        box-shadow: 0 1px 1px rgba(0,0,0,.2);
        margin-right: 4px;
    }
    .demo-upload-list img{
        width: 100%;
        height: 100%;
    }
    .demo-upload-list-cover{
        display: none;
        position: absolute;
        top: 0;
        bottom: 0;
        left: 0;
        right: 0;
        background: rgba(0,0,0,.6);
    }
    .demo-upload-list:hover .demo-upload-list-cover{
        display: block;
    }
    .demo-upload-list-cover i{
        color: #fff;
        font-size: 20px;
        cursor: pointer;
        margin: 0 2px;
    }
</style>

    這個功能是可以實現的，大家可以嘗試一下，會有驚喜哦！