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vue-pdf查看pdf文件及打印乱码问题处理

前言

vue中简单使用vue-pdf预览pdf文件,解决打印预览乱码问题

vue-pdf 使用

安装

npm install --save vue-pdf

引入

import pdf from "vue-pdf

自定义封装pdf预览组件

<template>
  <el-dialog
    :visible.sync="pdfDialog"
    :close-on-click-modal="false"
    :show-close="false"
    width="900px"
    top="52px"
  >
    <div class="pdf" v-show="fileType == 'pdf'">
      <p class="arrow">
        <!-- 上一页 -->
        <span
          @click="changePdfPage(0)"
          class="currentPage"
          :class="{ grey: currentPage == 1 }"
          >上一页&nbsp;&nbsp;</span
        >
        <span style="color: #8c8e92;">{{ currentPage }} / {{ pageCount }}</span>
        <!-- 下一页 -->
        <span
          @click="changePdfPage(1)"
          class="currentPage"
          :class="{ grey: currentPage == pageCount }"
          >&nbsp;&nbsp;下一页</span
        >&nbsp;&nbsp;&nbsp;&nbsp;<button @click="$refs.pdf.print()">下载</button>

        <span
          style="float :right;padding-right:40px;font-size: 20px;color: #8c8e92;cursor: pointer;"
          @click="close"
          ><i class="el-icon-close"></i
        ></span>
      </p>
      <!-- loadPdfHandler:加载事件 src:需要展示的PDF地址;currentPage:当前展示的PDF页码;pageCount=$event:PDF文件总页码;currentPage=$event:一开始加载的页面-->
      <pdf
         ref="pdf"
        :src="src"
        :page="currentPage"
        @num-pages="pageCount = $event"
        @page-loaded="currentPage = $event"
        @loaded="loadPdfHandler"
      ></pdf>
    </div>
  </el-dialog>
</template>

<script>
import pdf from "vue-pdf";
export default {
  components: { pdf },
  props: ["src"],
  data() {
    return {
      filesProps: {
        label: "originName"
      },
      pdfDialog: false,
      currentPage: 0, // pdf文件页码
      pageCount: 0, // pdf文件总页数
      fileType: "pdf" // 文件类型
    };
  },
  methods: {
    // 改变PDF页码,val传过来区分上一页下一页的值,0上一页,1下一页
    changePdfPage(val) {
      if (val === 0 && this.currentPage > 1) {
        this.currentPage--;
      }
      if (val === 1 && this.currentPage < this.pageCount) {
        this.currentPage++;
      }
    },
    // pdf加载时
    loadPdfHandler() {
      this.currentPage = 1; // 加载的时候先加载第一页
    },
    handleOpen() {
      this.pdfDialog = true;
    },
    //关闭弹框
    close() {
      this.pdfDialog = false;
    }
  }
};
</script>

<style lang="stylus">
.currentPage {
    cursor: pointer;
    color: #8c8e92;
}

.currentPage:hover {
    color: #2761ff;
}
.arrow{
    position: fixed;
    top: 0px;
    left :0px;
    z-index: 2;
    width: 100%;
    background-color: #191919;
    padding: 12px 0;
    margin: 0;
    text-align :center;
}
>>>.el-dialog__body {
    color: #606266;
    font-size: 14px;
    padding:0;
}
</style>

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使用

<template>
  <el-container>
    <el-header>
      <el-card>
        <div>
          <el-button
            style="font-style:oblique;font-size: 18px;"
            @click="handlePreviewFile"
            >PDF 预览</el-button
          >
          <el-button
            style="float: right;line-height: 40px;padding: 3px;"
            type="text"
            @click="handleSafetyExperience"
            ><i class="el-icon-caret-left">返回</i></el-button
          >
        </div>
      </el-card>
    </el-header>
    <el-main>
      <el-card class="card-style">
        <pdf-preview ref="pdfSearch" :src="src"></pdf-preview>
      </el-card>
    </el-main>
  </el-container>
</template>

<script>
import PdfPreview from "../widget/PdfPreview";
export default {
  name: "InfoExperience",
  components: {
    PdfPreview
  },
  data() {
    return {
      src:
        "http://storage.xuetangx.com/public_assets/xuetangx/PDF/PlayerAPI_v1.0.6.pdf"
    };
  },
  created() {},
  methods: {
    handlePreviewFile() {
      this.$refs.pdfSearch.handleOpen();
    },
    handleSafetyExperience() {
      this.$router.push({ path: "/safetyApp/sharedExperience" });
    }
  }
};
</script>

<style scoped></style>

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预览效果

pdf文件预览

点击下载打印预览

预览出现乱码

预览乱码

pdf打印乱码解决办法

打开vue-pdf插件目录node_modules/vue-pdf/src/pdfjsWrapper.js

修改配置文件

解决办法

详见Github上提供解决办法 Fix fonts issue in printing #130

乱码解决,打印预览正常

正常打印预览

修改后pdfjsWrapper.js源码

以下为本人修改的pdfjsWrapper.js文件,亲测解决乱码问题

import { PDFLinkService } from 'pdfjs-dist/lib/web/pdf_link_service';

export default function(PDFJS) {

	function isPDFDocumentLoadingTask(obj) {

		return typeof(obj) === 'object' && obj !== null && obj.__PDFDocumentLoadingTask === true;
	}

	function createLoadingTask(src, options) {

		var source;
		if ( typeof(src) === 'string' )
			source = { url: src };
		else if ( src instanceof Uint8Array )
			source = { data: src };
		else if ( typeof(src) === 'object' && src !== null )
			source = Object.assign({}, src);
		else
			throw new TypeError('invalid src type');

		var loadingTask = PDFJS.getDocument(source);
		loadingTask.__PDFDocumentLoadingTask = true; // since PDFDocumentLoadingTask is not public

		if ( options && options.onPassword )
			loadingTask.onPassword = options.onPassword;

		if ( options && options.onProgress )
			loadingTask.onProgress = options.onProgress;

		return loadingTask;
	}


	function PDFJSWrapper(canvasElt, annotationLayerElt, emitEvent) {

		var pdfDoc = null;
		var pdfPage = null;
		var pdfRender = null;
		var canceling = false;

		canvasElt.getContext('2d').save();

		function clearCanvas() {

			canvasElt.getContext('2d').clearRect(0, 0, canvasElt.width, canvasElt.height);
		}

		function clearAnnotations() {

			while ( annotationLayerElt.firstChild )
				annotationLayerElt.removeChild(annotationLayerElt.firstChild);
		}

		this.destroy = function() {

			if ( pdfDoc === null )
				return;
			pdfDoc.destroy();
			pdfDoc = null;
		}

		this.getResolutionScale = function() {

			return canvasElt.offsetWidth / canvasElt.width;
		}

		this.printPage = function(dpi, pageNumberOnly) {

			if ( pdfPage === null )
				return;

			// 1in == 72pt
			// 1in == 96px
			var PRINT_RESOLUTION = dpi === undefined ? 150 : dpi;
			var PRINT_UNITS = PRINT_RESOLUTION / 72.0;
			var CSS_UNITS = 96.0 / 72.0;

			// var iframeElt = document.createElement('iframe');
			var printContainerElement = document.createElement('div');
			printContainerElement.setAttribute('id', 'print-container')

			// function removeIframe() {
			//
			// 	iframeElt.parentNode.removeChild(iframeElt);
			function removePrintContainer() {
				printContainerElement.parentNode.removeChild(printContainerElement);

			}

			new Promise(function(resolve, reject) {

				// iframeElt.frameBorder = '0';
				// iframeElt.scrolling = 'no';
				// iframeElt.width = '0px;'
				// iframeElt.height = '0px;'
				// iframeElt.style.cssText = 'position: absolute; top: 0; left: 0';
				//
				// iframeElt.onload = function() {
				//
				// 	resolve(this.contentWindow);
				// }
				//
				// window.document.body.appendChild(iframeElt);
				printContainerElement.frameBorder = '0';
				printContainerElement.scrolling = 'no';
				printContainerElement.width = '0px;'
				printContainerElement.height = '0px;'
				printContainerElement.style.cssText = 'position: absolute; top: 0; left: 0';

				window.document.body.appendChild(printContainerElement);
				resolve(window)
			})
			.then(function(win) {

				win.document.title = '';

				return pdfDoc.getPage(1)
				.then(function(page) {

					var viewport = page.getViewport(1);
					// win.document.head.appendChild(win.document.createElement('style')).textContent =
					printContainerElement.appendChild(win.document.createElement('style')).textContent =
					'@supports ((size:A4) and (size:1pt 1pt)) {' +
							'@page { margin: 1pt; size: ' + ((viewport.width * PRINT_UNITS) / CSS_UNITS) + 'pt ' + ((viewport.height * PRINT_UNITS) / CSS_UNITS) + 'pt; }' +
						'}' +

						'#print-canvas { display: none }' +

						'@media print {' +
							'body { margin: 0 }' +
							'canvas { page-break-before: avoid; page-break-after: always; page-break-inside: avoid }' +
						'#print-canvas { page-break-before: avoid; page-break-after: always; page-break-inside: avoid; display: block }' +
						'body > *:not(#print-container) { display: none; }' +
						'}'+

						'@media screen {' +
							'body { margin: 0 }' +
						// '}'+
						//
						// ''
						'}'
					return win;
				})
			})
			.then(function(win) {

				var allPages = [];

				for ( var pageNumber = 1; pageNumber <= pdfDoc.numPages; ++pageNumber ) {

					if ( pageNumberOnly !== undefined && pageNumberOnly.indexOf(pageNumber) === -1 )
						continue;

					allPages.push(
						pdfDoc.getPage(pageNumber)
						.then(function(page) {

							var viewport = page.getViewport(1);

							// var printCanvasElt = win.document.body.appendChild(win.document.createElement('canvas'));
							var printCanvasElt = printContainerElement.appendChild(win.document.createElement('canvas'));
							printCanvasElt.setAttribute('id', 'print-canvas')

							printCanvasElt.width = (viewport.width * PRINT_UNITS);
							printCanvasElt.height = (viewport.height * PRINT_UNITS);

							return page.render({
								canvasContext: printCanvasElt.getContext('2d'),
								transform: [ // Additional transform, applied just before viewport transform.
									PRINT_UNITS, 0, 0,
									PRINT_UNITS, 0, 0
								],
								viewport: viewport,
								intent: 'print'
							}).promise;
						})
					);
				}

				Promise.all(allPages)
				.then(function() {

					win.focus(); // Required for IE
					if (win.document.queryCommandSupported('print')) {
						win.document.execCommand('print', false, null);
						} else {
						win.print();
					  }
					// removeIframe();
					removePrintContainer();
				})
				.catch(function(err) {

					// removeIframe();
					removePrintContainer();
					emitEvent('error', err);
				})
			})
		}

		this.renderPage = function(rotate) {
			if ( pdfRender !== null ) {

				if ( canceling )
					return;
				canceling = true;
				pdfRender.cancel();
				return;
			}

			if ( pdfPage === null )
				return;

			if ( rotate === undefined )
				rotate = pdfPage.rotate;

			var scale = canvasElt.offsetWidth / pdfPage.getViewport(1).width * (window.devicePixelRatio || 1);
			var viewport = pdfPage.getViewport(scale, rotate);

			emitEvent('page-size', viewport.width, viewport.height);

			canvasElt.width = viewport.width;
			canvasElt.height = viewport.height;

			pdfRender = pdfPage.render({
				canvasContext: canvasElt.getContext('2d'),
				viewport: viewport
			});

			annotationLayerElt.style.visibility = 'hidden';
			clearAnnotations();

			var viewer = {
				scrollPageIntoView: function(params) {
					emitEvent('link-clicked', params.pageNumber)
				},
			};

			var linkService = new PDFLinkService();
			linkService.setDocument(pdfDoc);
			linkService.setViewer(viewer);

			pdfPage.getAnnotations({ intent: 'display' })
			.then(function(annotations) {

				PDFJS.AnnotationLayer.render({
					viewport: viewport.clone({ dontFlip: true }),
					div: annotationLayerElt,
					annotations: annotations,
					page: pdfPage,
					linkService: linkService,
					renderInteractiveForms: false
				});
			});

			pdfRender
			.then(function() {
				annotationLayerElt.style.visibility = '';
				canceling = false;
				pdfRender = null;
			})
			.catch(function(err) {

				pdfRender = null;
				if ( err instanceof PDFJS.RenderingCancelledException ) {

					canceling = false;
					this.renderPage(rotate);
					return;
				}
				emitEvent('error', err);
			}.bind(this))
		}


		this.forEachPage = function(pageCallback) {

			var numPages = pdfDoc.numPages;

			(function next(pageNum) {

				pdfDoc.getPage(pageNum)
				.then(pageCallback)
				.then(function() {

					if ( ++pageNum <= numPages )
						next(pageNum);
				})
			})(1);
		}


		this.loadPage = function(pageNumber, rotate) {

			pdfPage = null;

			if ( pdfDoc === null )
				return;

			pdfDoc.getPage(pageNumber)
			.then(function(page) {

				pdfPage = page;
				this.renderPage(rotate);
				emitEvent('page-loaded', page.pageNumber);
			}.bind(this))
			.catch(function(err) {

				clearCanvas();
				clearAnnotations();
				emitEvent('error', err);
			});
		}

		this.loadDocument = function(src) {

			pdfDoc = null;
			pdfPage = null;

			emitEvent('num-pages', undefined);

			if ( !src ) {

				canvasElt.removeAttribute('width');
				canvasElt.removeAttribute('height');
				clearAnnotations();
				return;
			}

			if ( isPDFDocumentLoadingTask(src) ) {

				if ( src.destroyed ) {

					emitEvent('error', new Error('loadingTask has been destroyed'));
					return
				}

				var loadingTask = src;
			} else {

				var loadingTask = createLoadingTask(src, {
					onPassword: function(updatePassword, reason) {

						var reasonStr;
						switch (reason) {
							case PDFJS.PasswordResponses.NEED_PASSWORD:
								reasonStr = 'NEED_PASSWORD';
								break;
							case PDFJS.PasswordResponses.INCORRECT_PASSWORD:
								reasonStr = 'INCORRECT_PASSWORD';
								break;
						}
						emitEvent('password', updatePassword, reasonStr);
					},
					onProgress: function(status) {

						var ratio = status.loaded / status.total;
						emitEvent('progress', Math.min(ratio, 1));
					}
				});
			}

			loadingTask
			.then(function(pdf) {

				pdfDoc = pdf;
				emitEvent('num-pages', pdf.numPages);
				emitEvent('loaded');
			})
			.catch(function(err) {

				clearCanvas();
				clearAnnotations();
				emitEvent('error', err);
			})
		}

		annotationLayerElt.style.transformOrigin = '0 0';
	}

	return {
		createLoadingTask: createLoadingTask,
		PDFJSWrapper: PDFJSWrapper,
	}
}

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