Vue3+element-plus图片上传剪裁组件

userAvatar.vue

<template>
  <div class="user-info-head" @click="editCropper()">
    <img :src="options.img" title="点击上传头像" class="img-circle img-lg" />
    <el-dialog
      :title="title"
      v-model="open"
      width="800px"
      append-to-body
      @opened="modalOpened"
      @close="closeDialog"
    >
      <el-row>
        <el-col :xs="24" :md="12" :style="{ height: '350px' }">
          <vue-cropper
            ref="cropper"
            :img="options.img"
            :info="true"
            :autoCrop="options.autoCrop"
            :autoCropWidth="options.autoCropWidth"
            :autoCropHeight="options.autoCropHeight"
            :fixedBox="options.fixedBox"
            :outputType="options.outputType"
            @realTime="realTime"
            v-if="visible"
          />
        </el-col>
        <el-col :xs="24" :md="12" :style="{ height: '350px' }">
          <div class="avatar-upload-preview">
            <img :src="options.previews.url" :style="options.previews.img" />
          </div>
        </el-col>
      </el-row>
      <br />
      <el-row>
        <el-col :lg="2" :md="2">
          <el-upload
            action="#"
            :http-request="requestUpload"
            :show-file-list="false"
            :before-upload="beforeUpload"
          >
            <el-button>
              选择
              <el-icon class="el-icon--right"><Upload /></el-icon>
            </el-button>
          </el-upload>
        </el-col>
        <el-col :lg="{ span: 1, offset: 2 }" :md="2">
          <el-button icon="Plus" @click="changeScale(1)"></el-button>
        </el-col>
        <el-col :lg="{ span: 1, offset: 1 }" :md="2">
          <el-button icon="Minus" @click="changeScale(-1)"></el-button>
        </el-col>
        <el-col :lg="{ span: 1, offset: 1 }" :md="2">
          <el-button icon="RefreshLeft" @click="rotateLeft()"></el-button>
        </el-col>
        <el-col :lg="{ span: 1, offset: 1 }" :md="2">
          <el-button icon="RefreshRight" @click="rotateRight()"></el-button>
        </el-col>
        <el-col :lg="{ span: 2, offset: 6 }" :md="2">
          <el-button type="primary" @click="uploadImg()">提 交</el-button>
        </el-col>
      </el-row>
    </el-dialog>
  </div>
</template>

<script setup>
import "vue-cropper/dist/index.css";
import { VueCropper } from "vue-cropper";
import { uploadAvatar } from "@/api/login";
import useUserStore from "@/store/modules/user";
const userStore = useUserStore();
const { proxy } = getCurrentInstance();

const open = ref(false);
const visible = ref(false);
const title = ref("修改头像");

//图片裁剪数据
const options = reactive({
  img: userStore.avatar, // 裁剪图片的地址
  autoCrop: true, // 是否默认生成截图框
  autoCropWidth: 200, // 默认生成截图框宽度
  autoCropHeight: 200, // 默认生成截图框高度
  fixedBox: true, // 固定截图框大小 不允许改变
  outputType: "png", // 默认生成截图为PNG格式
  previews: {}, //预览数据
});

/** 编辑头像 */
function editCropper() {
  open.value = true;
}
/** 打开弹出层结束时的回调 */
function modalOpened() {
  nextTick(() => {
    visible.value = true;
  });
}
/** 覆盖默认上传行为 */
function requestUpload() {}
/** 向左旋转 */
function rotateLeft() {
  proxy.$refs.cropper.rotateLeft();
}
/** 向右旋转 */
function rotateRight() {
  proxy.$refs.cropper.rotateRight();
}
/** 图片缩放 */
function changeScale(num) {
  num = num || 1;
  proxy.$refs.cropper.changeScale(num);
}
/** 上传预处理 */
function beforeUpload(file) {
  if (file.type.indexOf("image/") == -1) {
    proxy.$modal.msgError(
      "文件格式错误，请上传图片类型,如：JPG，PNG后缀的文件。"
    );
  } else {
    const reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = () => {
      options.img = reader.result;
    };
  }
}
/** 上传图片 */
function uploadImg() {
  // 获取截图的 base64 数据
  proxy.$refs.cropper.getCropData((data) => {
    // let formData = new FormData();
    // formData.append("avatarfile", data);
    let img = new Image();
    img.src = data;
    img.onload = async () => {
      let _data = compress(img);
      // console.log(_data)
      uploadAvatar({ avatar: _data }).then((response) => {
        open.value = false;
        options.img = response.data.avatar;
        userStore.avatar = userStore.user.avatar = options.img;
        userStore.saveUser(userStore.user);
        proxy.$modal.msgSuccess("修改成功");
        visible.value = false;
      });
    };
  });
}
// 压缩图片
function compress(img) {
  let canvas = document.createElement("canvas");
  let ctx = canvas.getContext("2d");
  // let initSize = img.src.length;
  let width = img.width;
  let height = img.height;
  canvas.width = width;
  canvas.height = height;
  // 铺底色
  ctx.fillStyle = "#fff";
  ctx.fillRect(0, 0, canvas.width, canvas.height);
  ctx.drawImage(img, 0, 0, width, height);
  // 进行压缩
  let ndata = canvas.toDataURL("image/jpeg", 0.8);
  return ndata;
}
/** 实时预览 */
function realTime(data) {
  options.previews = data;
}
/** 关闭窗口 */
function closeDialog() {
  options.img = userStore.avatar;
  options.visible = false;
}
</script>

<style lang="scss" scoped>
.user-info-head {
  position: relative;
  display: inline-block;
  height: 120px;
}

.user-info-head:hover:after {
  content: "+";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  color: #eee;
  background: rgba(0, 0, 0, 0.5);
  font-size: 24px;
  font-style: normal;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  cursor: pointer;
  line-height: 110px;
  border-radius: 50%;
}
</style>

箴言：因为这些东西是非常简单的。不要抱怨自己学不会，那是因为你没有足够用心。