PDF预览

因为平时经常会遇到各种pdf预览，所以封装了一个pdf预览组件，方便自己使用。

1. 首先安装vue-pdf-embed和vue3-pdfjs第三方库

npm install vue-pdf-embed --save

npm install vue3-pdfjs --save

2.预览组件的相关代码,支持分页、放大缩小功能。

<template>
  <div class="center" v-if="loading">加载中。。。</div>
  <div class="pdf-preview" v-else>
    <div class="pdf-wrap">
      <vue-pdf-embed :source="state.source" :style="scale" class="vue-pdf-embed" :page="state.pageNum" />
    </div>
    <div class="page-tool">
      <div class="page-tool-item" @click="lastPage">
        <StepBackwardOutlined />
      </div>
      <div class="page-tool-item" @click="nextPage">
        <StepForwardOutlined />
      </div>
      <div class="page-tool-item">{{ state.pageNum }}/{{ state.numPages }}</div>
      <div class="page-tool-item" @click="pageZoomOut">
        <ZoomInOutlined />
      </div>
      <div class="page-tool-item" @click="pageZoomIn">
        <ZoomOutOutlined />
      </div>
    </div>
  </div>
</template>
<script setup>
import { reactive, onMounted, computed, watch } from "vue";
import VuePdfEmbed from "vue-pdf-embed";
import { createLoadingTask } from "vue3-pdfjs/esm";
import { StepBackwardOutlined, StepForwardOutlined, ZoomInOutlined, ZoomOutOutlined } from "@ant-design/icons-vue";

const props = defineProps({
  pdfUrl: {
    type: String,
    required: true,
  },
});

const state = reactive({
  source: props.pdfUrl, //预览pdf文件地址
  pageNum: 1, //当前页面
  scale: 1, // 缩放比例
  numPages: 0, // 总页数
});

const scale = computed(() => `transform:scale(${state.scale})`);

const lastPage = () => {
  if (state.pageNum > 1) {
    state.pageNum -= 1;
  }
};

const nextPage = () => {
  if (state.pageNum < state.numPages) {
    state.pageNum += 1;
  }
};

const pageZoomOut = () => {
  if (state.scale < 2) {
    state.scale += 0.1;
  }
};

const pageZoomIn = () => {
  if (state.scale > 0.1) {
    state.scale -= 0.1;
  }
};

const loading = ref(true);

onMounted(() => {
  showPdf();
});

const showPdf = () => {
  console.log(state.source);
  if (!state.source) {
    return;
  }
  loading.value = true;
  const loadingTask = createLoadingTask(state.source);
  loadingTask.promise.then((pdf) => {
    state.numPages = pdf.numPages;
    loading.value = false;
  });
};

watch(
  () => props.pdfUrl,
  (newVal, oldVal) => {
    if (newVal) {
      state.source = JSON.parse(JSON.stringify(newVal));
      showPdf();
    }
  },
  {
    immediate: true,
    deep: true,
  }
);
</script>
<style lang="css" scoped>
.pdf-preview {
  position: relative;
  height: calc(100vh - 50px);
  padding: 20px 0;
  box-sizing: border-box;
  background-color: e9e9e9;
}

.pdf-wrap {
  overflow-y: auto;
}

.vue-pdf-embed {
  text-align: center;
  width: 500px;
  border: 1px solid #e5e5e5;
  margin: 0 auto;
  box-sizing: border-box;
}

.page-tool {
  position: absolute;
  bottom: 35px;
  padding-left: 15px;
  padding-right: 15px;
  display: flex;
  align-items: center;
  background: rgb(66, 66, 66);
  color: white;
  border-radius: 19px;
  z-index: 100;
  cursor: pointer;
  margin-left: 50%;
  transform: translateX(-50%);
}

.page-tool-item {
  padding: 8px 15px;
  padding-left: 10px;
  cursor: pointer;
}
</style>