零碎页面中有时候会有一些加载 pdf 资源的性能需要,pdfjs-dist 这个插件能够满足要求。
解决步奏:申请 -> 转换 -> 加载
这里应用的版本是 2.2.228
申请有两种,一种能够是 Url 链接申请。一种是二进制文件。代码上差异不大, 业务逻辑解决如下:
const winW = (document.querySelector('.pdf-calssname') as HTMLDivElement).getBoundingClientRect().width;
const loadingFile = PDFJS.getDocument('your url'); // URL
const laodingFile = PDFJS.getDocument({data:atob(blod)}); // 二进制文件
//loading....
loadingFile.promise.then((pdf)=>{
const nums = pdf.numPages;
setpageNum(new Array(nums).fill(1)); // pageNum variable
for(let i =1;i<nums;++i){pdf.getPage(i).then((page:any)=>{const viewport:any = page.getViewport(i);
const scale:any = (winW / viewport.width).toFixed(2); //url
cosnt scale:any = (winW /viewport.width *viewport.scale).toFixed(2) // 二进制文件流
const scaledViewport = page.getViewport({scale:Math.max(scale,1)*2});
const canvas:any = document.getElementById('the-canvas'+i);
const context = canvas.getContext('2d');
canvas.height = Math.ceil(scaleViewport.height);
canvas.width = Math.ceil(scaleViewport.width);
const renderContext ={
canvasContext:context,
viewport:scaledViewport,
}
const render:any = page.render(renderContext);
render.then((=>{})
})
}
},(err)=>{console.log(err);
})
局部 tsx
代码如下:
<div className = 'pdfdetail-innderbox'>
{pageNum.map((v:number,i:number)=>{<canvas key={i} id = {`the-canvas${i+1}`} className = 'pdf-content'>
})
}
</div>