vue3+vant4实现pdf文件上传与预览组件

npm i  pdfjs-dist@2.2.228

<!--预览pdf文件的组件-->
<template>
  <van-overlay :show="show" @click="close()">
    <div class="pdf-viewer" >
      <van-swipe class="my-swipe" indicator-color="red" @click.stop>
        <van-swipe-item v-for="item in pageNum" :key="item">
          <canvas :id="`pdf-canvas-${item}`" class="pdf-page"/>
        </van-swipe-item>
        <template #indicator="{ active, total }">
          <div class="custom-indicator">{{ active + 1 }}/{{ total }}</div>
        </template>
      </van-swipe>
      <van-empty
          v-if="loadError"
          image="error"
          description="PDF加载出错了..."
      />
    </div>
    <van-icon name="close" color="#fff" size="0.3rem"/>
  </van-overlay>

</template>

<script setup lang="tsx">
import {ref, nextTick, watch} from 'vue';
import {closeToast, showLoadingToast, showSuccessToast} from "vant";

// 引入pdf预览插件相关的参数，注意这块开始试了很多网上方法都不好用
import * as pdfjs from 'pdfjs-dist';
import pdfjsWorker from 'pdfjs-dist/build/pdf.worker?url';
// 设置 worker 路径
pdfjs.GlobalWorkerOptions.workerSrc = pdfjsWorker;


const show = ref(true);
// html部分涉及的参数
const loadError = ref(false);
const detail = ref({});
let pdfDoc = null; // 一定不能使用响应式的数据，会报错Cannot read from private field---pdf.js
const pageNum = ref(0);


const props = defineProps({
  pdfUrl: {
    type: String,
    default: ""
  },
})
const emit= defineEmits(['close'])

watch(() => props.pdfUrl, (newVal) => {
  // console.log("监听", newVal, props.pdfUrl)
  showLoadingToast('加载中');
  nextTick(() => {
    loadingPdf(props.pdfUrl);
  })

}, {immediate: true,deep:true})
// 防抖 debounce 函数的实现正确。
const debounce(func, wait, options = {}) {
    let timeout;
    const { leading = false, trailing = true } = options;

    return function(...args) {
        const later = () => {
            timeout = null;
            if (!leading) func.apply(this, args);
        };

        const callNow = leading && !timeout;
        clearTimeout(timeout);
        timeout = setTimeout(later, wait);

        if (callNow) func.apply(this, args);
    };
}
// 使用防抖函数，300ms内只执行一次，避免多次点击立刻打开又关闭的情况
const close = debounce(() => {
  show.value = false;
  emit('close')
}, 300, { leading: true, trailing: false });

//加载pdf
const loadingPdf = (url) => {
  const afterUrl = {
    url,
    httpHeaders: {
      token: `Bearer-${localStorage.getItem('token')}`,//微信小程序里面打开这个模块，发现请求401，报错信息是登陆访问超时，发现pdfjs加载pdf时没有携带token,于是在加载url时添加token即可
    },
  };
  const loadingTask = pdfjs.getDocument(afterUrl);
  loadingTask.promise
      .then((pdf) => {
        pdfDoc = pdf;
        pageNum.value = pdf.numPages;
        nextTick(() => {
          renderPage();
        });
      })
      .catch(() => {
        loadError.value = true;
      });
}

// 渲染pdf
const renderPage = (num = 1) => {
  pdfDoc.getPage(num).then((page) => {
    const canvas = document.getElementById(`pdf-canvas-${num}`);
    if(!canvas){return}
    const ctx = canvas.getContext('2d');
    const scale = 1.5;
    const viewport = page.getViewport({scale});
    // 画布大小,默认值是width:300px,height:150px
    canvas.height = viewport.height;
    canvas.width = viewport.width;
    // 画布的dom大小, 设置移动端,宽度设置铺满整个屏幕
    const {clientWidth} = document.body;
    // 减去2rem使用因为我的页面左右加了padding
    canvas.style.width = `calc(${clientWidth}px - 2rem)`;
    // 根据pdf每页的宽高比例设置canvas的高度
    canvas.style.height = `${
        clientWidth * (viewport.height / viewport.width)
    }px`;
    canvas.height = viewport.height;
    canvas.width = viewport.width;
    page.render({
      canvasContext: ctx,
      viewport,
    });
    //隐藏渲染所有的页面
    if (num < pageNum.value) {
      renderPage(num + 1);
    } else {
      closeToast();
    }
  });
}

</script>

<style scoped>
.pdf-viewer{
  display: flex;
  justify-content: center;
  align-items: center;
  height:100vh;
  width:100vw;
  text-align: center;
}
.custom-indicator {
  position: absolute;
  left: 50%;
  bottom: 15px;
  transform: translateX(-50%);
  padding: 2px 5px;
  font-size: 18px;
  color: #fff;
  background: rgba(0, 0, 0, 0.1);
}
</style>

import PdfPreview from "@/components/PdfPreview/index.vue";
// 点击预览文件
const showPreview=(file)=>{
  if(file.absoluteUrl.endsWith('.pdf')){
    pdfUrl.value=file.absoluteUrl;
    preview.value=true;
  }
}

<template>
  <div class="upload-box1">
   
    <van-uploader
        v-model="_fileList"
        list-type="picture-card"
        :class="['upload', self_disabled ? 'disabled' : '']"
        :multiple="false"
        :disabled="self_disabled"
        :max-count="props.limit"
        :after-read="handleHttpUpload"
        :before-read="beforeUpload"
        :before-delete="handleRemove"
        :accept="props.fileType"
        :deletable="props.deletable"
        upload-icon="plus"
        :max-size="500 * 1024* 1000"
        :preview-image="true"
        :preview-size="props.width"
        :reupload="props.reupload"
        @oversize="onOversize"
    >
    </van-uploader>
//我的展示效果里面有个文字。所以在下面加了这个.
    <div v-for="item in _fileList" :key="item.url" v-if="_fileList.length>0" >
      <div name="tips" class="tips" style="width:70px">{{props.tips}}</div>
    </div>

    <div class="tips" :style="{'width':props.width}" v-else>
      <div name="tips">{{props.tips}}</div>
    </div>

  </div>
</template>

<script setup lang="tsx" name="UploadImgs">
import { ref, computed, inject, watch } from "vue";
import { removeImg, uploadFile } from "@/api/modules/upload";//封装的接口

import {showFailToast,showSuccessToast } from 'vant';
import type { UploaderFileListItem, ImagePreviewOptions } from 'vant';

//上传的内容参数
interface UploaderFileList {
  url:string,
  name:string,
  absoluteUrl:string,
  businessCode:string,
  businessSubCode:string,
  businessId:string,
  resourceId:string,
}
interface UploadFileProps {
  fileList: UploaderFileList[];
  disabled?: boolean; // 是否禁用上传组件 ==> 非必传（默认为 false）
  limit?: number; // 最大图片上传数 ==> 非必传（默认为 5张）
  nowLimit?:number;//当前页面只有一个图片的地方。图片上传的数量限制
  fileSize?: number; // 图片大小限制 ==> 非必传（默认为 5M）
  fileType?:string; // 类型限制 ==> 非必传（默认为 "image/jpeg", "image/png", "image/gif","application/pdf"）
  height?: string; // 组件高度 ==> 非必传（默认为 60px）
  width?: string; // 组件宽度 ==> 非必传（默认为 60px）
  borderRadius?: string; // 组件边框圆角 ==> 非必传（默认为 8px）
  uploadParams?: any; //上传带的参数==>必填
  tips?:string;
  deletable?:boolean;
  reupload?:boolean;//是否可重复上传==>非必填默认false。不可重复上传。点击图片是预览效果
}

const props = withDefaults(defineProps<UploadFileProps>(), {
  fileList:()=> [],
  disabled: false,
  limit: 5,
  nowLimit:1,
  fileSize: 5,
  fileType: "image/jpeg, image/png, image/gif, application/pdf",
  height: "60px",
  width: "60px",
  borderRadius: "8px",
  uploadParams: {},
  tips:"上传",
  deletable:true,
  reupload:false
});
const emit = defineEmits(["update:fileList", "update"]);


// 判断是否禁用上传和删除
const self_disabled = computed(() => {
  return props.disabled
});

const _fileList =  ref<UploaderFileList[]>(props.fileList)
const uploadFileData = ref(); //上传的文件

// 监听 props.fileList 列表默认值改变
watch(
    () => props.fileList,
    (n) => {
      _fileList.value = n.map(res=>{
        return {
          url:res.absoluteUrl||'',//展示的时候需要url但是接口给我回传的里面没有。所以这里自己拼接一下
          name:res.name||'',
          absoluteUrl:res.absoluteUrl||'',
          businessCode:res.businessCode||'',
          businessSubCode:res.businessSubCode||'',
          businessId:res.businessId||'',
          resourceId:res.resourceId||'',
        }
      });
    }
);

/**
 * @description 文件上传之前判断
 * @param rawFile 选择的文件
 * */
const beforeUpload= (rawFile) => {
  console.log(rawFile)
  const imgSize = rawFile.size / 1024 / 1024 < props.fileSize;
  const imgType = props.fileType.includes(rawFile.type);
  if (!imgType)
    showFailToast( "上传文件不符合所需的格式！");
  if (!imgSize)
    setTimeout(() => {
      showFailToast( `上传文件大小不能超过 ${props.fileSize}M！`);
    }, 0);
  return imgType && imgSize;
};


const onOversize=()=>{
  showFailToast( `上传文件大小不能超过 ${props.fileSize}M！`);
}
/**
 * @description 图片上传,请求接口
 * @param options upload 所有配置项
 * */
const handleHttpUpload = async (options: any) => {
  // console.log("handleHttpUpload", options.file)
//二进制内容上传参数
  let formData = new FormData();
  formData.append("uploadFile", options.file);
  for (let key in props.uploadParams) {
    formData.append(key, props.uploadParams[key]);
  }

  try {
    const api = uploadFile;//上传接口全局一样，可以直接写死
    const { data,code } = await api(formData);
    if(code==200){
     //把接口返回的值给到操作的这个file，相当于更新了_fileList.value
      options.businessCode = data.businessCode;
      options.businessSubCode = data.businessSubCode;
      options.resourceId = data.resourceId;
      options.businessId = data.businessId;
      options.absoluteUrl = data.absoluteUrl;
      options.url = data.absoluteUrl;

      emit("update", { data: data });
      showSuccessToast( "上传成功！");
      console.log("上传成功fileList：",_fileList.value)
      emit("update:fileList",_fileList.value);
    }else{
      uploadError();
    }
  } catch (error) {
    console.log(error as any);
  }
};



/**
 * @description 删除图片
 * @param file 删除的文件
 * */
// 提取过滤逻辑为独立函数，增强可读性和复用性
function shouldRemoveItem(item, file) {
  // 检查每个属性是否完全匹配，避免逻辑错误
  return (
      item.url === file.url &&
      item.name === file.name &&
      item.absoluteUrl === file.absoluteUrl
  );
}
const handleRemove = async (file: UploaderFileListItem, detail: { index: number }) => {
  // console.log("删除",file,detail)
  // 应用过滤逻辑，过滤掉已经删除的内容
  _fileList.value = _fileList.value.filter((item) => !shouldRemoveItem(item, file));
  console.log("删除",_fileList.value)
  let deleteParam = {
    sysCode: "aged",
    businessCode: file.businessCode,
    businessSubCode: file.businessSubCode,
    businessId: file.businessId,
    resourceIds: [file.resourceId],
  };

 let [code]= await removeImg(deleteParam);
 if(code==200){
   showSuccessToast( "删除成功！");
 }
  emit("update:fileList", _fileList.value);
};

/**
 * @description 图片上传错误
 * */
const uploadError = () => {
  showFailToast( "上传失败，请您重新上传！");
};

/**
 * @description 文件数超出
 * */
const handleExceed = () => {
  showFailToast("当前最多只能上传"+(props.nowLimit||8)+"份，请移除后上传！");
};


</script>

<style scoped lang="scss">
</style>

<template>
  <Upload :upload-params="serviceOtherParams" v-model:file-list="img3" :limit="6" tips="上传内容">
  </Upload>
</template>

​​​​​​​<script lang="ts" setup>
import Upload from "@/components/Upload/index.vue";
const img3=ref([])
//定义要传递的参数
const serviceOtherParams = reactive({
  sysCode: "aged",
  businessCode: "serviceOrderRecord",
  businessSubCode: "serviceOther",
});
</script>