背景

需求背景是用户粘贴截图或者复制的图片后，需要自动上传文件后端。

效果图：

实现思路是：
利用input输入自带的方法paste。根据文件类型来判定是不是图片，如果是图片就把文件上传到后端。

<template>
  <div class="main">
    <el-input
      type="textarea"
      :rows="2"
      placeholder="粘贴图片即上传附件"
      v-model="textarea"
      @paste.native="handlePaste"
    >
    </el-input>
    <el-upload
      class="upload-demo"
      action="https://jsonplaceholder.typicode.com/posts/"
      :on-preview="handlePreview"
      :on-remove="handleRemove"
      :before-remove="beforeRemove"
      multiple
      :limit="3"
      :on-exceed="handleExceed"
      :file-list="fileList"
    >
      <el-button size="small" type="primary">点击上传</el-button>
      <div slot="tip" class="el-upload__tip">
        只能上传jpg/png文件，且不超过500kb
      </div>
    </el-upload>
  </div>
</template>

<script>
export default {
  data() {
    return {
      fileList: [
        {
          name: "food.jpeg",
          url: "https://fuss10.elemecdn.com/3/63/4e7f3a15429bfda99bce42a18cdd1jpeg.jpeg?imageMogr2/thumbnail/360x360/format/webp/quality/100",
        },
        {
          name: "food2.jpeg",
          url: "https://fuss10.elemecdn.com/3/63/4e7f3a15429bfda99bce42a18cdd1jpeg.jpeg?imageMogr2/thumbnail/360x360/format/webp/quality/100",
        },
      ],
      textarea: "",
    };
  },
  methods: {
    handleRemove(file, fileList) {
      console.log(file, fileList);
    },
    handlePreview(file) {
      console.log(file);
    },
    handleExceed(files, fileList) {
      this.$message.warning(
        `当前限制选择 3 个文件，本次选择了 ${files.length} 个文件，共选择了 ${
          files.length + fileList.length
        } 个文件`
      );
    },
    handlePaste(value) {
      let items = value.clipboardData.items[0]
      if(items.type.includes('image')) {
        this.file = items.getAsFile()
        //正常流程应该是用拿到的file文件，使用formData去上传到后端，拿到后端返回的图片链接push进去fileList
        this.fileList.push({
          name: "food2.jpeg",
          url: "https://fuss10.elemecdn.com/3/63/4e7f3a15429bfda99bce42a18cdd1jpeg.jpeg?imageMogr2/thumbnail/360x360/format/webp/quality/100",
        },)
      }
      console.log(this.file, '粘贴内容')
    },
    beforeRemove(file, fileList) {
      return this.$confirm(`确定移除 ${file.name}？`);
    },
  },
};
</script>
<style lang="scss" scoped>
  .main {
    margin: 50px 300px;
  }
  .upload-demo {
    margin-top: 30px;
  }
</style>