vue-pdf查看pdf文件及打印亂碼問題處理

前言

vue中簡單使用vue-pdf預覽pdf文件，解決打印預覽亂碼問題

vue-pdf 使用

安裝

npm install --save vue-pdf

引入

import pdf from "vue-pdf

自定義封裝pdf預覽組件

<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">
        <!-- 上一頁 -->
        <span @click="changePdfPage(0)" class="currentPage" :class="{ grey: currentPage == 1 }" >上一頁&nbsp;&nbsp;</span >
        <span style="color: #8c8e92;">{{ currentPage }} / {{ pageCount }}</span>
        <!-- 下一頁 -->
        <span @click="changePdfPage(1)" class="currentPage" :class="{ grey: currentPage == pageCount }" >&nbsp;&nbsp;下一頁</span >&nbsp;&nbsp;&nbsp;&nbsp;<button @click="$refs.pdf.print()">下載</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：加載事件 src：須要展現的PDF地址；currentPage：當前展現的PDF頁碼；pageCount=$event：PDF文件總頁碼；currentPage=$event：一開始加載的頁面-->
      <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文件頁碼 pageCount: 0, // pdf文件總頁數 fileType: "pdf" // 文件類型 }; }, methods: { // 改變PDF頁碼,val傳過來區分上一頁下一頁的值,0上一頁,1下一頁 changePdfPage(val) { if (val === 0 && this.currentPage > 1) { this.currentPage--; } if (val === 1 && this.currentPage < this.pageCount) { this.currentPage++; } }, // pdf加載時 loadPdfHandler() { this.currentPage = 1; // 加載的時候先加載第一頁 }, handleOpen() { this.pdfDialog = true; }, //關閉彈框 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 預覽</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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預覽效果

點擊下載打印預覽

預覽出現亂碼

pdf打印亂碼解決辦法

打開vue-pdf插件目錄node_modules/vue-pdf/src/pdfjsWrapper.js

解決辦法

詳見Github上提供解決辦法 Fix fonts issue in printing #130

亂碼解決，打印預覽正常

修改後pdfjsWrapper.js源碼

如下爲本人修改的pdfjsWrapper.js文件，親測解決亂碼問題

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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