typescript Angular 6 - 无法将 Base64 转换为 PDF
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时间：2020-10-21 05:36:07 来源:igfitidea点击:
Angular 6 - Unable to Convert Base64 to PDF
提问by Tora Tora Tora
I'm attempting to convert a Base64 string to PDF and download it in the browser, and the generated PDF is not readable:
我正在尝试将 Base64 字符串转换为 PDF 并将其下载到浏览器中，但生成的 PDF 不可读：
app.component.html ->
app.component.html ->
<div style="text-align:center">
<form>
<div class="form-row text-center">
<button type="button" class="btn div-button" (click)="showPdf()">PDF</button>
</div>
</form>
</div>
app.component.ts ->
app.component.ts ->
import {Component} from '@angular/core';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
showPdf() {
const pdfInBase64 = '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\n';
const newBlob = new Blob([pdfInBase64], {type: 'application/pdf'});
if (window.navigator && window.navigator.msSaveOrOpenBlob) {
window.navigator.msSaveOrOpenBlob(newBlob); // For IE browser
}
const linkElement = document.createElement('a');
const url = URL.createObjectURL(newBlob);
linkElement.setAttribute('href', url);
linkElement.setAttribute('download', 'sample.pdf');
const clickEvent = new MouseEvent('click', {
'view': window,
'bubbles': true,
'cancelable': false
});
linkElement.dispatchEvent(clickEvent);
}
}
The PDF gets downloaded in the browser. However, it's not readable.
PDF 会在浏览器中下载。但是，它不可读。
What am I missing?
我错过了什么？
回答by Sachi.Dila
You can use this code in the showPdf function to generate the PDF, Hope this helps
您可以在 showPdf 函数中使用此代码生成 PDF，希望这会有所帮助
showPdf() {
const linkSource = 'data:application/pdf;base64,' + 'JVBERi0xLjMNCiXi48/TDQoNCjEgMCBvYmoNCjw8DQovVHlwZSAvQ2F0YWxvZw0KL091dGxpbmVzIDIgMCBSDQovUGFnZXMgMyAwIFINCj4+DQplbmRvYmoNCg0KMiAwIG9iag0KPDwNCi9UeXBlIC9PdXRsaW5lcw0KL0NvdW50IDANCj4+DQplbmRvYmoNCg0KMyAwIG9iag0KPDwNCi9UeXBlIC9QYWdlcw0KL0NvdW50IDINCi9LaWRzIFsgNCAwIFIgNiAwIFIgXSANCj4+DQplbmRvYmoNCg0KNCAwIG9iag0KPDwNCi9UeXBlIC9QYWdlDQovUGFyZW50IDMgMCBSDQovUmVzb3VyY2VzIDw8DQovRm9udCA8PA0KL0YxIDkgMCBSIA0KPj4NCi9Qcm9jU2V0IDggMCBSDQo+Pg0KL01lZGlhQm94IFswIDAgNjEyLjAwMDAgNzkyLjAwMDBdDQovQ29udGVudHMgNSAwIFINCj4+DQplbmRvYmoNCg0KNSAwIG9iag0KPDwgL0xlbmd0aCAxMDc0ID4+DQpzdHJlYW0NCjIgSg0KQlQNCjAgMCAwIHJnDQovRjEgMDAyNyBUZg0KNTcuMzc1MCA3MjIuMjgwMCBUZA0KKCBBIFNpbXBsZSBQREYgRmlsZSApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDY4OC42MDgwIFRkDQooIFRoaXMgaXMgYSBzbWFsbCBkZW1vbnN0cmF0aW9uIC5wZGYgZmlsZSAtICkgVGoNCkVUDQpCVA0KL0YxIDAwMTAgVGYNCjY5LjI1MDAgNjY0LjcwNDAgVGQNCigganVzdCBmb3IgdXNlIGluIHRoZSBWaXJ0dWFsIE1lY2hhbmljcyB0dXRvcmlhbHMuIE1vcmUgdGV4dC4gQW5kIG1vcmUgKSBUag0KRVQNCkJUDQovRjEgMDAxMCBUZg0KNjkuMjUwMCA2NTIuNzUyMCBUZA0KKCB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDYyOC44NDgwIFRkDQooIEFuZCBtb3JlIHRleHQuIEFuZCBtb3JlIHRleHQuIEFuZCBtb3JlIHRleHQuIEFuZCBtb3JlIHRleHQuIEFuZCBtb3JlICkgVGoNCkVUDQpCVA0KL0YxIDAwMTAgVGYNCjY5LjI1MDAgNjE2Ljg5NjAgVGQNCiggdGV4dC4gQW5kIG1vcmUgdGV4dC4gQm9yaW5nLCB6enp6ei4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kICkgVGoNCkVUDQpCVA0KL0YxIDAwMTAgVGYNCjY5LjI1MDAgNjA0Ljk0NDAgVGQNCiggbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDU5Mi45OTIwIFRkDQooIEFuZCBtb3JlIHRleHQuIEFuZCBtb3JlIHRleHQuICkgVGoNCkVUDQpCVA0KL0YxIDAwMTAgVGYNCjY5LjI1MDAgNTY5LjA4ODAgVGQNCiggQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgKSBUag0KRVQNCkJUDQovRjEgMDAxMCBUZg0KNjkuMjUwMCA1NTcuMTM2MCBUZA0KKCB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBFdmVuIG1vcmUuIENvbnRpbnVlZCBvbiBwYWdlIDIgLi4uKSBUag0KRVQNCmVuZHN0cmVhbQ0KZW5kb2JqDQoNCjYgMCBvYmoNCjw8DQovVHlwZSAvUGFnZQ0KL1BhcmVudCAzIDAgUg0KL1Jlc291cmNlcyA8PA0KL0ZvbnQgPDwNCi9GMSA5IDAgUiANCj4+DQovUHJvY1NldCA4IDAgUg0KPj4NCi9NZWRpYUJveCBbMCAwIDYxMi4wMDAwIDc5Mi4wMDAwXQ0KL0NvbnRlbnRzIDcgMCBSDQo+Pg0KZW5kb2JqDQoNCjcgMCBvYmoNCjw8IC9MZW5ndGggNjc2ID4+DQpzdHJlYW0NCjIgSg0KQlQNCjAgMCAwIHJnDQovRjEgMDAyNyBUZg0KNTcuMzc1MCA3MjIuMjgwMCBUZA0KKCBTaW1wbGUgUERGIEZpbGUgMiApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDY4OC42MDgwIFRkDQooIC4uLmNvbnRpbnVlZCBmcm9tIHBhZ2UgMS4gWWV0IG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gKSBUag0KRVQNCkJUDQovRjEgMDAxMCBUZg0KNjkuMjUwMCA2NzYuNjU2MCBUZA0KKCBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSB0ZXh0LiBBbmQgbW9yZSApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDY2NC43MDQwIFRkDQooIHRleHQuIE9oLCBob3cgYm9yaW5nIHR5cGluZyB0aGlzIHN0dWZmLiBCdXQgbm90IGFzIGJvcmluZyBhcyB3YXRjaGluZyApIFRqDQpFVA0KQlQNCi9GMSAwMDEwIFRmDQo2OS4yNTAwIDY1Mi43NTIwIFRkDQooIHBhaW50IGRyeS4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gQW5kIG1vcmUgdGV4dC4gKSBUag0KRVQNCkJUDQovRjEgMDAxMCBUZg0KNjkuMjUwMCA2NDAuODAwMCBUZA0KKCBCb3JpbmcuICBNb3JlLCBhIGxpdHRsZSBtb3JlIHRleHQuIFRoZSBlbmQsIGFuZCBqdXN0IGFzIHdlbGwuICkgVGoNCkVUDQplbmRzdHJlYW0NCmVuZG9iag0KDQo4IDAgb2JqDQpbL1BERiAvVGV4dF0NCmVuZG9iag0KDQo5IDAgb2JqDQo8PA0KL1R5cGUgL0ZvbnQNCi9TdWJ0eXBlIC9UeXBlMQ0KL05hbWUgL0YxDQovQmFzZUZvbnQgL0hlbHZldGljYQ0KL0VuY29kaW5nIC9XaW5BbnNpRW5jb2RpbmcNCj4+DQplbmRvYmoNCg0KMTAgMCBvYmoNCjw8DQovQ3JlYXRvciAoUmF2ZSBcKGh0dHA6Ly93d3cubmV2cm9uYS5jb20vcmF2ZVwpKQ0KL1Byb2R1Y2VyIChOZXZyb25hIERlc2lnbnMpDQovQ3JlYXRpb25EYXRlIChEOjIwMDYwMzAxMDcyODI2KQ0KPj4NCmVuZG9iag0KDQp4cmVmDQowIDExDQowMDAwMDAwMDAwIDY1NTM1IGYNCjAwMDAwMDAwMTkgMDAwMDAgbg0KMDAwMDAwMDA5MyAwMDAwMCBuDQowMDAwMDAwMTQ3IDAwMDAwIG4NCjAwMDAwMDAyMjIgMDAwMDAgbg0KMDAwMDAwMDM5MCAwMDAwMCBuDQowMDAwMDAxNTIyIDAwMDAwIG4NCjAwMDAwMDE2OTAgMDAwMDAgbg0KMDAwMDAwMjQyMyAwMDAwMCBuDQowMDAwMDAyNDU2IDAwMDAwIG4NCjAwMDAwMDI1NzQgMDAwMDAgbg0KDQp0cmFpbGVyDQo8PA0KL1NpemUgMTENCi9Sb290IDEgMCBSDQovSW5mbyAxMCAwIFINCj4+DQoNCnN0YXJ0eHJlZg0KMjcxNA0KJSVFT0YNCg==\n';
const downloadLink = document.createElement("a");
const fileName = "sample.pdf";
downloadLink.href = linkSource;
downloadLink.download = fileName;
downloadLink.click();
}
回答by Juan
Your problem is that you are not decoding your base 64 PDF, use the function atob()to achieve this:
您的问题是您没有解码 base 64 PDF，请使用该功能atob()来实现：
var pdfInBase64 = atob(
'JVBERi0xLjcKCjEgMCBvYmogICUgZW50cnkgcG9pbnQKPDwKICAvVHlwZSAvQ2F0YWxvZwog' +
'IC9QYWdlcyAyIDAgUgo+PgplbmRvYmoKCjIgMCBvYmoKPDwKICAvVHlwZSAvUGFnZXMKICAv' +
'TWVkaWFCb3ggWyAwIDAgMjAwIDIwMCBdCiAgL0NvdW50IDEKICAvS2lkcyBbIDMgMCBSIF0K' +
'Pj4KZW5kb2JqCgozIDAgb2JqCjw8CiAgL1R5cGUgL1BhZ2UKICAvUGFyZW50IDIgMCBSCiAg' +
'L1Jlc291cmNlcyA8PAogICAgL0ZvbnQgPDwKICAgICAgL0YxIDQgMCBSIAogICAgPj4KICA+' +
'PgogIC9Db250ZW50cyA1IDAgUgo+PgplbmRvYmoKCjQgMCBvYmoKPDwKICAvVHlwZSAvRm9u' +
'dAogIC9TdWJ0eXBlIC9UeXBlMQogIC9CYXNlRm9udCAvVGltZXMtUm9tYW4KPj4KZW5kb2Jq' +
'Cgo1IDAgb2JqICAlIHBhZ2UgY29udGVudAo8PAogIC9MZW5ndGggNDQKPj4Kc3RyZWFtCkJU' +
'CjcwIDUwIFRECi9GMSAxMiBUZgooSGVsbG8sIHdvcmxkISkgVGoKRVQKZW5kc3RyZWFtCmVu' +
'ZG9iagoKeHJlZgowIDYKMDAwMDAwMDAwMCA2NTUzNSBmIAowMDAwMDAwMDEwIDAwMDAwIG4g' +
'CjAwMDAwMDAwNzkgMDAwMDAgbiAKMDAwMDAwMDE3MyAwMDAwMCBuIAowMDAwMDAwMzAxIDAw' +
'MDAwIG4gCjAwMDAwMDAzODAgMDAwMDAgbiAKdHJhaWxlcgo8PAogIC9TaXplIDYKICAvUm9v' +
'dCAxIDAgUgo+PgpzdGFydHhyZWYKNDkyCiUlRU9G');
回答by Hansaka Sandaruwan
you can use jspdfto download image as pdf. I use html2canvasto generate my base64image.
您可以使用jspdf将图像下载为 pdf。我使用html2canvas来生成我的 base64image。
var pdf = new jspdf("l", "mm", [288, 288]);
pdf.addImage(
base64String,
"PNG",
0,
position,
imageWidth,
imgHeight
);
pdf.save("cv.pdf"); // download PDF
