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
上一页
{{ currentPage }} / {{ pageCount }}
下一页
使用
PDF 预览
返回
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,
}
}