学习目标：

我们在开发后台时肯定避免不了上传图片的功能

例如：

• 上传图片回显
• 上传完成 : 预览查看 , 删除等
• 如果是图片列表,还可能让你拖动图片排序
• 有的后台项目可能要给图片添加水印,添加标记
• 有的后台可能要炫酷一点 添加进度条功能

---

学习内容：

现在我们要完成上面的一系列功能,这里我用到了vue element ui的弹窗组件,预览图片组件,还有axios,axios是二次封装的,你们可以自行根据你们的项目来封装

效果演示:

---

上传图片组件代码

<!--
 * @Author: 等风来 [email protected]
 * @Date: 2022-11-10 08:42:34
 * @LastEditTime: 2023-02-17 11:07:40
-->
<template>
  <div class="UploadImg_list">
    <transition-group name="tag" class="UploadImg_list">
      <div
        v-for="(item, index) in imgList"
        :key="item.id"
        :draggable="true"
        class="UploadImg_item"
        @dragstart="dragstart(index)"
        @dragenter="dragenter($event, index)"
        @dragover="dragover($event, index)"
      >
        <div class="item_cont">
          <img :src="item.url" alt="" />
          <div class="img_mask">
            <i
              class="el-icon-zoom-in"
              style="margin-right: 10px"
              @click="lookImg(item)"
            ></i>
            <i class="el-icon-delete" @click="delImg(item)"></i>
          </div>
        </div>
      </div>
      <div
        v-if="imgList.length < form.total"
        :key="-999999999"
        class="UploadImg_input"
        @click="showUploadImg"
      >
        <i class="el-icon-plus"></i>
      </div>
    </transition-group>
    <el-image
      ref="preview"
      class="nones"
      :src="url"
      :preview-src-list="srcList"
    ></el-image>
    <div v-show="is_Ball" class="my_mask">
      <Ball :percent="ballNum" :run-num="runNum"></Ball>
    </div>
    <!-- 对话框 -->
    <div class="UploadImg">
      <el-dialog
        title="上传图片配置"
        :close-on-click-modal="false"
        :visible.sync="isUploadImg"
        width="500px"
        :append-to-body="true"
      >
        <div>
          <el-form ref="form" :model="form" label-width="70px">
            <el-form-item v-if="form.total" label="图片总数">
              <el-input-number
                v-model="form.total"
                :min="1"
                :max="maxNum"
                :disabled="maxNumHide"
                label="图片总数"
                style="width: 100%"
              ></el-input-number>
            </el-form-item>
            <el-form-item label="图片尺寸">
              <el-switch v-model="form.size"></el-switch>
            </el-form-item>
            <el-form-item v-if="form.size" label="图片宽度">
              <el-input-number
                v-model="form.width"
                :min="50"
                label="图片宽度"
                style="width: 100%"
              ></el-input-number>
            </el-form-item>
            <el-form-item v-if="form.size" label="图片高度">
              <el-input-number
                v-model="form.height"
                :min="50"
                label="图片高度"
                style="width: 100%"
              ></el-input-number>
            </el-form-item>
            <el-form-item label="图片类型">
              <el-checkbox-group v-model="form.imgTypes">
                <el-checkbox v-for="item in imgType" :key="item" :label="item">
                  {
   { item }}
                </el-checkbox>
              </el-checkbox-group>
            </el-form-item>
            <el-form-item label="是否水印">
              <el-switch v-model="form.Watermark"></el-switch>
            </el-form-item>
            <el-form-item v-if="form.Watermark" label="水印文字">
              <el-input
                v-model="form.title"
                maxlength="6"
                show-word-limit
              ></el-input>
            </el-form-item>
            <el-form-item label="是否多选">
              <div>
                <el-switch v-model="form.Multiple"></el-switch>
                <span v-if="!form.Multiple" style="margin-left: 10px">
                  当前进度条功能开启
                </span>
                <span v-else style="margin-left: 10px">当前进度条功能关闭</span>
              </div>
              <p class="MultipleTitle">
                单选时开启进度条功能,多选则关闭进度条功能
              </p>
            </el-form-item>
          </el-form>
        </div>
        <span slot="footer" class="dialog-footer UploadImg_btn">
          <el-button @click="isUploadImg = false">取 消</el-button>
          <el-button type="primary">
            选择图片
            <input
              v-if="form.Multiple"
              type="file"
              accept="image/*"
              multiple="multiple"
              @change="addImgs"
            />
            <input v-else type="file" accept="image/*" @change="addImgs" />
          </el-button>
        </span>
      </el-dialog>
    </div>
  </div>
</template>

<script>
  import Ball from '../../components/Ball/index.vue'
  export default {
    name: 'UploadImg',
    components: { Ball: Ball },
    props: {
      //图片数据
      lists: {
        type: Array,
        default() {
          return []
        },
      },
      //图片限制个数
      maxNum: {
        type: Number,
        default() {
          return 5
        },
      },
      //图片限制是否能调整
      maxNumHide: {
        type: Boolean,
        default() {
          return false
        },
      },
      //图片类型限制
      imgType: {
        type: Array,
        default() {
          // return ['image/jpeg', 'image/png']
          return ['image/jpeg']
        },
      },
      //是否限制图片尺寸
      isSize: {
        type: Boolean,
        default() {
          return false
        },
      },
      //限制图片尺寸大小
      imgSize: {
        type: Array,
        default() {
          return [400, 400]
        },
      },
      //是否水印
      isWatermark: {
        type: Boolean,
        default() {
          return false
        },
      },
      //水印文字
      watermarkTitle: {
        type: String,
        default() {
          return '默认水印'
        },
      },
      // 1 选择图片是否多选
      // 2 false 时开启进度条功能
      isMultiple: {
        type: Boolean,
        default() {
          return true
        },
      },
    },
    data() {
      return {
        imgList: this.lists,
        url: '',
        srcList: [],
        // 源对象的下标
        dragIndex: '',
        // 目标对象的下标
        enterIndex: '',
        timeout: null,
        isUploadImg: false,
        form: {
          total: this.maxNum,
          size: this.isSize,
          width: this.imgSize[0],
          height: this.imgSize[1],
          title: this.watermarkTitle,
          Watermark: this.isWatermark,
          Multiple: this.isMultiple,
          imgTypes: [...this.imgType],
        },
        ballNum: 0,
        is_Ball: false,
        runNum: 0,
      }
    },
    watch: {
      maxNum: {
        handler: function (a, b) {
          this.form.total = a
        },
        // deep: true,
      },
    },
    methods: {
      // 显示上传图片对话框
      showUploadImg() {
        this.isUploadImg = true
      },
      // 上传图片前置验证
      addImgBefore(fileArr) {
        return new Promise((resolve, reject) => {
          let isOk = true
          // 上传图片数量限制
          if (this.imgList.length + fileArr.length > this.form.total) {
            if (this.imgList.length > this.form.total) {
              const del_nums = this.imgList.length - this.form.total
              this.imgList.splice(this.form.total, del_nums)
            }
            this.$message.error(`最多上传 ${this.form.total} 张图片!`)
            return resolve(false)
          }
          // 上传图片类型限制
          if (this.form.imgTypes.length > 0) {
            fileArr.forEach((item) => {
              if (this.form.imgTypes.indexOf(item.type) < 0) {
                isOk = false
              }
            })
            if (!isOk) {
              this.$message.error(
                `上传图片中类型不符合 ${this.form.imgTypes.toString()} 类型 !`
              )
              return resolve(false)
            }
          }
          //上传图片判断尺寸
          if (this.form.size) {
            fileArr.forEach((fileItem) => {
              this.limitFileWH(
                this.form.width,
                this.form.height,
                fileItem
              ).then((res) => {
                if (res) {
                  return resolve(true)
                } else {
                  return resolve(false)
                }
              })
            })
          } else {
            resolve(true)
          }
        })
      },
      // 上传图片
      async addImgs(e) {
        let file = [...e.target.files]
        let isOk = await this.addImgBefore(file)
        // 前置验证
        if (!isOk) {
          return
        }
        if (file.length > 1) {
          this.runNum = 0.5
        } else {
          this.runNum = 3
        }
        // 是否开启进度条
        if (!this.form.Multiple && file.length > 0) {
          this.is_Ball = true
        }
        this.ballNum = 0
        if (this.form.Watermark) {
          // 有水印的
          file.forEach(async (item) => {
            this.getBase64(item).then((res) => {
              this.imgToCanvas(res).then((data) => {
                this.imgList.push({
                  id: new Date().valueOf(),
                  url: data,
                })
                this.ballNum = 0
                this.is_Ball = false
              })
            })
          })
        } else {
          // 不加水印的
          file.forEach(async (item) => {
            const res = await this.$http.post(
              'admin/api/upload',
              {
                file: item,
                disk: 'public',
                folder: 'richText',
              },
              {
                headers: {
                  'Content-Type': 'multipart/form-data',
                },
                onUploadProgress: (progressEvent) => {
                  let persent =
                    ((progressEvent.loaded / progressEvent.total) * 100) | 0 //上传进度百分比
                  this.ballNum = persent
                },
              }
            )
            if (res.code == 200000) {
              this.imgList.push({
                id: new Date().valueOf(),
                url: res.data.url,
              })
              this.ballNum = 0
              this.is_Ball = false
              this.$message.success(res.message)
            } else {
              this.$message.error(res.message)
              this.is_Ball = false
              return
            }
          })
        }
        this.isUploadImg = false
      },
      // 判断图片是否正方形
      limitFileWH(E_width, E_height, file) {
        const _this = this
        let imgWidth = ''
        let imgHight = ''
        const isSize = new Promise(function (resolve, reject) {
          const width = E_width
          const height = E_height
          const _URL = window.URL || window.webkitURL
          const img = new Image()
          img.onload = function () {
            imgWidth = img.width
            imgHight = img.height
            const valid = img.width === width && img.height === height
            valid ? resolve() : reject()
          }
          img.src = _URL.createObjectURL(file)
        }).then(
          () => {
            return true
          },
          () => {
            _this.$message.warning({
              message:
                '上传图片的尺寸应为' +
                E_width +
                '*' +
                E_height +
                '，当前上传图片的尺寸为：' +
                imgWidth +
                '*' +
                imgHight,
              btn: false,
            })
            return false
          }
        )
        return isSize
      },
      // 转64
      getBase64(file) {
        return new Promise(function (resolve, reject) {
          const reader = new FileReader()
          let imgResult = ''
          reader.readAsDataURL(file)
          reader.onload = function () {
            imgResult = reader.result
          }
          reader.onerror = function (error) {
            reject(error)
          }
          reader.onloadend = function () {
            resolve(imgResult)
          }
        })
      },
      // 64转文件
      dataURLtoFile(dataurl, filename) {
        var arr = dataurl.split(',')
        var mime1 = arr[0].split(';')
        var mime2 = mime1[0].split(':')[1]
        var bstr = atob(arr[1])
        var n = bstr.length
        var u8arr = new Uint8Array(n)
        while (n--) {
          u8arr[n] = bstr.charCodeAt(n)
        }
        return new File([u8arr], 'names', { type: mime2 })
      },
      // 画水印 并上传
      imgToCanvas(imgSrc) {
        return new Promise((resolve, reject) => {
          const _this = this
          var image = document.createElement('img')
          image.setAttribute('src', imgSrc)
          const img_Src = ''
          // 创造画布
          image.onload = async () => {
            var canvas = document.createElement('canvas')
            canvas.width = image.width
            canvas.height = image.height
            var cxt = canvas.getContext('2d')
            // 将图片绘制上去
            cxt.drawImage(image, 0, 0) // 第一个参数是图片（不能是src 否则会报错，是src的话需要先new Image()，具体看上个getImgWay方法） 第二、三是图片在画布位置 第四、五是将图片绘制成多大宽高（不写四五就是原图宽高）
            // 给画布上添加水印文字
            cxt.font = '24px Georgia'
            cxt.textAlign = 'left'
            cxt.textBaseline = 'top'
            cxt.fillStyle = '#fff'
            //   cxt.rotate(-10 * Math.PI / 180)
            cxt.rotate((Math.PI / 180) * 5)
            if (image.height > image.width) {
              for (let i = 0; i < image.height / 200; i++) {
                for (let j = 0; j < image.width / 50; j++) {
                  cxt.fillText(this.form.title, i * 300, j * 100, image.width)
                }
              }
            } else {
              for (let i = 0; i < image.width / 200; i++) {
                for (let j = 0; j < image.height; j++) {
                  cxt.fillText(this.form.title, i * 300, j * 100, image.width)
                }
              }
            }
            var dataurl = canvas.toDataURL('image/png')
            // 转好的文件 可根据你们的后端接口自行上传
            const file = this.dataURLtoFile(dataurl)
            // const formdata = new FormData()
            // formdata.append('file', file)
            const res = await this.$http.post(
              'admin/api/upload',
              {
                file: file,
                disk: 'public',
                folder: 'richText',
              },
              {
                headers: {
                  'Content-Type': 'multipart/form-data',
                },
                onUploadProgress: (progressEvent) => {
                  let persent =
                    ((progressEvent.loaded / progressEvent.total) * 100) | 0 //上传进度百分比
                  this.ballNum = persent
                },
              }
            )
            // const { data: res } = await $http.post('api/upload', formdata)
            if (res.code != 200000) {
              this.$message.error(res.message)
              this.is_Ball = false
              resolve(false)
              return
            }
            resolve(res.data.url)
            this.$message.success(res.message)
          }
        })
      },
      // 删除图片
      delImg(item) {
        this.$confirm('确定删除该张图片吗?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning',
        })
          .then(() => {
            let num = -1
            this.imgList.forEach((i, index) => {
              if (item.url == i.url) {
                num = index
              }
            })
            this.imgList.splice(num, 1)
            this.$message({
              type: 'success',
              message: '删除成功!',
            })
          })
          .catch(() => {})
      },
      // 查看图片
      lookImg(item) {
        this.srcList = []
        this.imgList.forEach((i, index) => {
          this.srcList.push(i.url)
        })
        this.url = item.url
        this.$refs.preview.clickHandler()
      },
      // 拖动排序
      dragstart(index) {
        this.dragIndex = index
      },

      // dragenter 和 dragover 事件的默认行为是拒绝接受任何被拖放的元素。
      // 因此，我们要在这两个拖放事件中使用`preventDefault`来阻止浏览器的默认行为
      dragenter(e, index) {
        let indexs = -1
        e.preventDefault()
        this.enterIndex = index
        if (this.timeout !== null) {
          clearTimeout(this.timeout)
        }
        // 拖拽事件的防抖
        this.timeout = setTimeout(() => {
          if (this.dragIndex !== index) {
            const source = this.imgList[this.dragIndex]
            this.imgList.splice(this.dragIndex, 1)
            this.imgList.splice(index, 0, source)
            // 排序变化后目标对象的索引变成源对象的索引
            this.dragIndex = index
          }
        }, 250)
      },
      dragover(e, index) {
        e.preventDefault()
      },
    },
  }
</script>

<style lang="scss" scoped>
  .UploadImg_list {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    .UploadImg_item {
      transition: transform 0.3s;
      box-sizing: border-box;
      width: 90px;
      height: 90px;
      border: 1px solid #c0ccda;
      border-radius: 4px;
      margin-right: 5px;
      padding: 3px;
      cursor: move;
      margin: 5px 0;
      margin-right: 5px;
      margin-bottom: 0;
      i {
        cursor: pointer !important;
      }
      .item_cont {
        position: relative;
        box-sizing: border-box;
        width: 100%;
        height: 100%;
        // background-color: red;
        border-radius: 2px;
        overflow: hidden;
        border: 1px solid #c0ccda;
        transition: all 0.3s;
        img {
          transition: all 0.3s;
          width: 100%;
          height: auto;
        }
      }
      .img_mask {
        position: absolute;
        left: 0;
        top: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.4);
        display: flex;
        align-items: center;
        justify-content: center;
        color: #fff;
        font-size: 20px;
        opacity: 0;
      }
    }
    .UploadImg_input {
      float: left;
      position: relative;
      width: 90px;
      height: 90px;
      border: 1px dashed #c0ccda;
      box-sizing: border-box;
      border-radius: 4px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 20px;
      color: #c0ccda;
      margin: 5px 0;
      margin-bottom: 0;
      cursor: pointer !important;
      background-color: #fbfdff;
    }
    .UploadImg_input:hover {
      border: 1px dashed #0187fb;
      color: #0187fb;
    }
    .UploadImg_item:hover {
      box-shadow: 0 2px 12px 0 rgb(1 133 249 / 60%);
      border: 1px solid hsl(208, 99%, 49%);
    }
    .UploadImg_item:hover img {
      transform: scale(1.4);
    }
    .UploadImg_item:hover .img_mask {
      opacity: 1;
    }
  }
  .nones {
    display: none;
  }

  .tag-enter-active {
    animation: tagFrames 0.3s linear;
  }
  .tag-leave-active {
    animation: tagFrames 0.3s linear reverse;
  }
  @keyframes tagFrames {
    from {
      transform: translateY(-30px);
      opacity: 0;
    }
    to {
      opacity: 1;
      transform: translateY(0px);
    }
  }
  ::v-deep .UploadImg .el-dialog__title {
    font-weight: 700;
  }
  ::v-deep .UploadImg .el-form-item__label {
    font-weight: 700;
  }
  ::v-deep .UploadImg .el-dialog__body {
    border: none;
  }
  ::v-deep .UploadImg .el-dialog__footer {
    border: none;
  }
  ::v-deep .UploadImg_btn .el-button span {
    cursor: pointer !important;
  }
  .UploadImg_btn .el-button {
    width: 90px;
    height: 36px;
    font-size: 15px;
    // line-height: 36px;
    position: relative;
    cursor: pointer;
    input {
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      width: 100%;
      height: 100%;
      cursor: pointer !important;
    }
  }
  .my_mask {
    position: fixed;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    z-index: 99999999999;
    background-color: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .MultipleTitle {
    margin: 0;
    color: #f56c6c;
    font-size: 14px;
  }
</style>

进度条小球组件代码

<template>
  <div class="pie-wrap">
    <div
      :style="{ animationDelay: delay }"
      :class="['pie', { 'pie-all': num == 100 }]"
    >
      <div class="pie-inner">
        <p class="percent">{
   { num }}%</p>
        <p class="txt">上传中...</p>
      </div>
    </div>
  </div>
</template>

<script>
  export default {
    name: 'Pie',
    props: {
      percent: {
        type: Number,
        default: 0,
      },
      runNum: {
        type: Number,
        default: 3,
      },
    },
    data() {
      return {
        num: 0,
      }
    },
    computed: {
      delay() {
        // 转化为延迟多少秒
        return `-${this.num}s`
      },
    },
    watch: {
      percent() {
        this.startAnimate(this.runNum, this.percent, 5)
      },
    },
    mounted() {
      this.startAnimate(this.runNum, this.percent, 5)
    },
    methods: {
      // 匀动动画
      startAnimate(step, limit, speed) {
        setTimeout(() => {
          if (this.num < limit) {
            this.num += step
            this.startAnimate(step, limit, speed)
          } else {
            this.num = limit
          }
        }, speed)
      },
    },
  }
</script>

<style lang="scss" scoped>
  .pie-wrap {
    width: 100%;
    height: 200px;
    text-align: center;
    .pie {
      display: inline-block;
      position: relative;
      width: 160px;
      height: 160px;
      margin-top: 40px;
      border-radius: 50%;
      background: #ccc;
      background-image: linear-gradient(to right, transparent 50%, #4479fd 0);
      color: transparent;
      text-align: center;
    }
    .pie::before {
      content: '';
      position: absolute;
      top: 0;
      left: 50%;
      width: 50%;
      height: 100%;
      border-radius: 0 100% 100% 0 / 50%;
      background-color: inherit;
      transform-origin: left;
      animation: spin 50s linear infinite, bg 100s step-end infinite;
      animation-play-state: paused;
      animation-delay: inherit;
    }
    .pie-all {
      background: #4479fd;
      background-image: none;
    }
    .pie-all::before {
      background-color: #4479fd;
    }
    @keyframes spin {
      to {
        transform: rotate(0.5turn);
      }
    }
    @keyframes bg {
      50% {
        background: #4479fd;
      }
    }
    .pie-inner {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      width: 90%;
      height: 90%;
      border-radius: 50%;
      background: #fff;
      transform: translate(-50%, -50%);
      .percent {
        margin-top: 38px;
        margin-bottom: 10px;
        font-size: 30px;
        color: #000;
      }
      .txt {
        font-size: 15px;
        color: #666;
        margin: 0;
      }
    }
  }
</style>

使用

<template>
  <div style="padding: 50px">
    <h1>上传图片(查看,删除,预览,拖动排序,水印,单个上传开启进度条)</h1>
    <upload-img
      :lists="imgList"
      :max-num="5"
      :img-type="['image/png']"
      :is-size="true"
      :img-size="[400, 400]"
      :is-watermark="true"
      :watermark-title="'默认水印'"
      :is-multiple="false"
    ></upload-img>
    <ul>
      <li v-for="item in imgList" :key="item.id">
        {
   { item.id }} -- {
   { item.url }}
      </li>
    </ul>
  </div>
</template>

<script>
  import uploadImg from '../../components/uploadImg/index.vue'
  export default {
    components: { 'upload-img': uploadImg },
    data() {
      return {
        imgList: [
          {
            id: 12,
            url: '*****',
          },
        ],
      }
    },
  }
</script>

<style></style>

注意:

        imgList格式一定要注意 id为唯一值 你们可以取当前时间戳 或者 后端返回的图片id

使用

1. lists 是图片数组数据 格式一定要对

2. max-num-hide 对话框 是否可以修改图片个数

3. max-num 是最多图片个数 不是选中图片个数

4. img-type 是图片类型 是数组 这里我没做处理 直接用的['image/jpeg', 'image/png']这种格式,你们想要修改,请自行修改

5. is-size 是上传图片前是否判断图片尺寸 根据 img-size 来判断 如果is-size 为false 那img-size 配置不生效

6. img-size 是限制图片尺寸 为数组 第一项为图片宽度 第二项为图片高度

7. is-watermark 是 是否开启水印功能 

8. watermark-title 是水印的文字 如果 is-watermark 为fasle啧该配置也无效

9. is-multiple 是选择图片是否为多选 true 为多选 ,false 为单选 单选是则开启上传进度条功能

这个组件并没有封装上传地址什么的 自行去源码修改 可根据你们后端的接口方式自行上传 很简单 你们肯定会

---

学习总结：

功能也算挺完善的一个上传图片组件,已知的就差裁剪功能了,如果有bug请联系我,谢谢,随便写着玩的