前言
之前做PDF预览一直用的pdf.js，这次没有太多附加需求比较简单简，所以决定用vue-pdf这个组件，虽然说它没有原生那样强大，但已经满足常用的需求了，重要是这个组件使用简单。顺便也把word文件和excel表格预览也整理了下，接下来我们直接进入正题！
一、预览word文件
1.安装 npm 依赖
npm i [email protected] npm i jszip
2.预览在线地址文件
3.预览本地文件
二、预览excel表格
1.安装依赖
npm i xlsx
2.预览在线表格
三、pdf预览
1.安装依赖vue-pdf
npm install --save vue-pdf
2.在需要的页面注册
3.使用
一般预览pdf时都是很多页的，为了提升性能可以做个分页。page: 当前显示的页数，比如第一页page=1；rotate ： 旋转角度，比如0就是不旋转，+90，-90 就是水平旋转。progress ：当前页面的加载进度，范围是0-1 ，等于1的时候代表当前页已经完全加载完成了。page-loaded ：页面加载成功的回调函数，不咋能用到。num-pages ：总页数；error ：加载错误的回调link-clicked：单机pdf内的链接会触发。print 这个是打印函数。（注意：谷歌浏览器预览时会出现乱码，这个问题是因为你pdf中使用了自定义字体导致的。若要解决须替换node_modules/vue-pdf/src/pdfjsWrapper.js，替换的pdfjsWrapper.js我放在文章最后）
上一页
下一页
{{pageNum}}/{{pageTotalNum}}
顺时针旋转
逆时针旋转
打印
4.加载本地pdf文件
如果需要加载本地pdf文件（不需要则不用配置），需要我们做一下本地配置flie-loader才行，否则webpack无法编译pdf类型的文件，配置方法也很简单，在项目根目录找到vue.config.js文件（若没有则在根目录下新建一个vue.config.js）。之后再url:require("…/assets/xxx.pdf")就没有任何问题了，注意，vue-pdf src接收的是string对象，如果直接传url这里报错了，需要传url.default一下。
先安装file-loader
npm install --save file-loader
然后在vue.config.js中加入以下内容：
module.exports = {
chainWebpack: config => {
const fileRule = config.module.rule('file')
fileRule.uses.clear()
fileRule
.test(/\.pdf|ico$/)
.use('file-loader')
.loader('file-loader')
.options({
limit: 10000,
})
},
publicPath: './'
}
5.解决pdf使用自定义字体预览和打印乱码问题：pdfjsWrapper.js
import { PDFLinkService } from 'pdfjs-dist/es5/web/pdf_viewer';
var pendingOperation = Promise.resolve();
export default function(PDFJS) {
function isPDFDocumentLoadingTask(obj) {
return typeof(obj) === 'object' && obj !== null && obj.__PDFDocumentLoadingTask === true;
// or: return obj.constructor.name === 'PDFDocumentLoadingTask';
}
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');
// source.verbosity = PDFJS.VerbosityLevel.INFOS;
// source.pdfBug = true;
// source.stopAtErrors = true;
if ( options && options.withCredentials )
source.withCredentials = options.withCredentials;
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;
// Aborts all network requests and destroys worker.
pendingOperation = 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 printContainerElement = document.createElement('div');
printContainerElement.setAttribute('id', 'print-container')
function removePrintContainer() {
printContainerElement.parentNode.removeChild(printContainerElement);
}
new Promise(function(resolve, reject) {
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({ scale: 1 });
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 }' +
'#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({ scale: 1 });
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();
}
removePrintContainer();
})
.catch(function(err) {
removePrintContainer();
emitEvent('error', err);
})
})
}
this.renderPage = function(rotate) {
if ( pdfRender !== null ) {
if ( canceling )
return;
canceling = true;
pdfRender.cancel().catch(function(err) {
emitEvent('error', err);
});
return;
}
if ( pdfPage === null )
return;
var pageRotate = (pdfPage.rotate === undefined ? 0 : pdfPage.rotate) + (rotate === undefined ? 0 : rotate);
var scale = canvasElt.offsetWidth / pdfPage.getViewport({ scale: 1 }).width * (window.devicePixelRatio || 1);
var viewport = pdfPage.getViewport({ scale: scale, rotation:pageRotate });
emitEvent('page-size', viewport.width, viewport.height, scale);
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);
pendingOperation = pendingOperation.then(function() {
var getAnnotationsOperation =
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
});
});
var pdfRenderOperation =
pdfRender.promise
.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))
return Promise.all([getAnnotationsOperation, pdfRenderOperation]);
}.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;
pendingOperation = pendingOperation.then(function() {
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;
}
// wait for pending operation ends
pendingOperation = pendingOperation.then(function() {
var loadingTask;
if ( isPDFDocumentLoadingTask(src) ) {
if ( src.destroyed ) {
emitEvent('error', new Error('loadingTask has been destroyed'));
return
}
loadingTask = src;
} else {
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));
}
});
}
return loadingTask.promise;
})
.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,
}
}
总结
到此这篇关于vue项目中常见的三种文件类型在线预览实现的文章就介绍到这了,更多相关vue文件在线预览内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！