<div>
  <!-- <input
    v-model="postModel.title_img"
    type="text"
    class="allInput"
  /> -->
  <el-upload
    class="images-uploader"
    action="#"
    :http-request="handelImageRequest"
    :show-file-list="false"
    :before-upload="beforeImagesUpload"
    :auto-upload="true"
  >
    <img
      v-if="postModel.title_img"
      :src="postModel.title_img"
      class="images"
    />
    <i v-else class="el-icon-plus images-uploader-icon"></i>
  </el-upload>
</div>

beforeImagesUpload(file) {
  const ext = file.type.split(‘/‘)[1];
  const isImg = [‘png‘, ‘jpg‘, ‘jpeg‘, ‘bmp‘, ‘gif‘, ‘webp‘, ‘psd‘, ‘svg‘, ‘tiff‘].indexOf(ext.toLowerCase()) !== -1;
  const isLt2M = file.size / 1024 / 1024 < 1;

  if (!isImg) {
    this.$message.error("请上传正确的图片文件!");
  }
  if (!isLt2M) {
    this.$message.error("图片大小不能超过1MB!");
  }
  return isImg && isLt2M;
},
handelImageRequest(param) {
  const formData = new FormData()
  formData.append(‘file‘, param.file)
  let config = {
      headers:{"Content-Type":"multipart/form-data"}
  };
  let that = this;
  this.$axios.post("/Upload/getImgUrl", formData , config ).then((p) => {
      // console.log(p); // 直接返回图片地址
      that.postModel.title_img = p;
  });      
}

<style scoped>
.images-uploader .el-upload {
  border: 1px dashed #d9d9d9;
  border-radius: 6px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.images-uploader .el-upload:hover {
  border-color: #409eff;
}
.images-uploader-icon {
  font-size: 28px;
  color: #8c939d;
  width: 178px;
  height: 178px;
  line-height: 178px;
  text-align: center;
  border:1px dashed #8c939d;
}
.images {
  width: 178px;
  height: 178px;
  display: block;
}
</style>

控制宽高

validWidth:200,
validHeight:200

beforeImagesUpload(file) {
  const ext = file.type.split("/")[1];
  const isImg =
    [
      "png",
      "jpg",
      "jpeg",
      "bmp",
      "gif",
      "webp",
      "psd",
      "svg",
      "tiff",
    ].indexOf(ext.toLowerCase()) !== -1;
  const isLt2M = file.size / 1024 / 1024 < 1;

  if (!isImg) {
    this.$message.error("请上传正确的图片文件!");
  }
  if (!isLt2M) {
    this.$message.error("图片大小不能超过1MB!");
  }

  // 验证图片宽高
  let isWHValid = true;
  if (this.validWidth && this.validHeight) {
    isWHValid = this.valWidthAndHeight(file);
  }

  return isImg && isLt2M && isWHValid;
},
handelImageRequest(param) {
  const formData = new FormData();
  formData.append("file", param.file);
  let config = {
    headers: { "Content-Type": "multipart/form-data" },
  };
  let that = this;
  this.$axios.post("/Upload/getImgUrl", formData, config).then((p) => {
    // console.log(p); // 直接返回图片地址
    that.postModel.title_img = p;
  });
},
//验证图片宽高
valWidthAndHeight: function (file) {
  let _this = this;
  return new Promise(function (resolve, reject) {
    let width = _this.validWidth; //图片宽度
    let height = _this.validHeight; //图片高度
    let _URL = window.URL || window.webkitURL;
    let image = new Image();
    image.src = _URL.createObjectURL(file);
    image.onload = function () {
      let valid = image.width == width && image.height == height;
      valid ? resolve() : reject();
    };
  }).then(
    () => {
      return file;
    },
    () => {
      this.$message.error(
        "上传图片尺寸不符合,只能是" +
          _this.validWidth +
          "*" +
          _this.validHeight +
          "!"
      );
      return Promise.reject();
    }
  );
}

Element UI 图片上传