我们如何在 Android 的 Cordova.inappbrowser 中显示 base 64 字符串中的 PDF

我的要求是在cordova中显示pdf base64字符串。在应用程序浏览器中，它没有显示在Android中

但它显示在iOS应用程序中。我正在使用以下代码在应用程序浏览器中显示PDF

$scope.urlString = "data:application/pdf;base64,"+encodeURI($scope.PdfString);
var ref = cordova.InAppBrowser.open($scope.urlString, '_blank',  'toolbarposition=bottom');

有谁知道如何在 Cordova InAppBrowser 中显示 PDF base64 字符串？或者有没有其他显示方式。

终于得到了解决方案我们需要在我们的项目中安装cordova-file-plugin

科尔多瓦插件添加科尔多瓦插件文件

var myBase64 = "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";
// To define the type of the Blob
var contentType = "application/pdf";
// if cordova.file is not available use instead :
// var folderpath = "file:///storage/emulated/0/";
var folderpath = cordova.file.externalRootDirectory;
var filename = "helloWorld.pdf";
savebase64AsPDF(folderpath,filename,$scope.PdfString,contentType);
function b64toBlob(b64Data, contentType, sliceSize) {
contentType = contentType || '';
sliceSize = sliceSize || 512;
var byteCharacters = atob(b64Data);
var byteArrays = [];
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize);
var byteNumbers = new Array(slice.length);
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
var byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
var blob = new Blob(byteArrays, {type: contentType});
return blob;
}
function savebase64AsPDF(folderpath,filename,content,contentType){
// Convert the base64 string in a Blob
var DataBlob = b64toBlob(content,contentType);
console.log("Starting to write the file :3");
window.resolveLocalFileSystemURL(folderpath, function(dir) {
console.log("Access to the directory granted succesfully");
		dir.getFile(filename, {create:true}, function(file) {
console.log("File created succesfully.");
file.createWriter(function(fileWriter) {
console.log("Writing content to file");
fileWriter.write(DataBlob);
console.log("Folder Path"+folderpath+filename);
var finalPath = folderpath+filename;
window.open(finalPath, '_system');
}, function(){
alert('Unable to save file in path '+ folderpath);
});
		});
});
}

只是为了补充@Byka的解决方案，我们应该在 ionic 3 中安装它

离子科尔多瓦插件

添加科尔多瓦插件文件
npm install --save @ionic-native/file
瓦插件添加科尔多瓦插件文件打开器2
npm install --save @ionic-native/file-opener

重要提示由于某种原因，文件中的 writeFile 不起作用，因此请编辑索引.html

你应该在你的科尔多瓦之前包括.js

<script src="build/polyfills.js"></script>

将插件添加到应用的模块

从"@ionic-本机/文件"导入 { 文件 } 从"@ionic-native/file-opener"导入 { FileOpener }

也添加到提供程序中

提供者： [ ..... 文件文件打开器 ]

import { Component } from '@angular/core'
import { NavController, NavParams, Platform } from 'ionic-angular'
import { InAppBrowser } from '@ionic-native/in-app-browser'
import { File } from '@ionic-native/file'
import { FileOpener } from '@ionic-native/file-opener'
@Component({
selector: 'page-pantalla-mi-promenal-consultas',
templateUrl: 'pantalla-mi-promenal-consultas.html'
})
export class YourPage {

constructor(
public navCtrl: NavController,
public navParams: NavParams,
private platform: Platform,
private file: File,
private fileOpener: FileOpener
) {}
getUserDataSheet() {
const blob = this.b64toBlob(pdfString, 'application/pdf', 512)
let pathFile = ''
const fileName = 'myPdf.pdf'
const contentFile = blob
if (this.platform.is('ios')) {
pathFile = this.file.documentsDirectory
} else {
pathFile = this.file.externalRootDirectory
}
this.file
.writeFile(pathFile, fileName, contentFile, { replace: true })
.then(success => {
this.fileOpener
.open(pathFile + fileName, 'application/pdf')
.then(data => {
this.inAppBrowser.create(data, '_system')
})
.catch(e => console.log('Error opening file', e))
})
.catch(e => console.log('Error writing file', e))
}
}
b64toBlob(b64Data, contentType, sliceSize = 512) {
contentType = contentType || ''
sliceSize = sliceSize || 512
b64Data = b64Data.replace(/^[^,]+,/, '')
b64Data = b64Data.replace(/s/g, '')
var byteCharacters = atob(b64Data)
var byteArrays = []
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize)
var byteNumbers = new Array(slice.length)
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i)
}
var byteArray = new Uint8Array(byteNumbers)
byteArrays.push(byteArray)
}
var blob = new Blob(byteArrays, {
type: contentType
})
// return byteCharacters;
return blob
}
}

就我而言，Byka的答案仅适用于Android。我编辑了它，现在它在 iOS 中也像魅力一样工作。我的应用程序下载 pdf base64 编码，转换并打开它。

问题是在iOS中打开文件，解决了添加文件打开器2插件的问题

function b64toBlob(b64Data, contentType, sliceSize) {
contentType = contentType || '';
sliceSize = sliceSize || 512;
var byteCharacters = atob(b64Data);
var byteArrays = [];
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize);
var byteNumbers = new Array(slice.length);
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
var byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
var blob = new Blob(byteArrays, { type: contentType });
return blob;
}
function savebase64AsPDF(folderpath, filename, content, contentType) {
// Convert the base64 string in a Blob
var DataBlob = b64toBlob(content, contentType);
window.resolveLocalFileSystemURL(folderpath, function (dir) {
dir.getFile(filename, { create: true }, function (file) {
file.createWriter(function (fileWriter) {
fileWriter.write(DataBlob);
var finalPath = folderpath + filename;
//window.open(finalPath, '_system');
cordova.plugins.fileOpener2.open(finalPath, 'application/pdf'
//,
//{
//    error: function (e) {
//        alert('Error status: ' + e.status + ' - Error message: ' + e.message);
//    },
//    success: function () {
//        alert('file opened successfully');
//    }
//}
);
}, function () {
alert("err");
});
});
}
function PrintFile(id) {
jQuery("#large-indicator").css("display", "inline");
$.ajax({
type: "POST",
contentType: "application/json",
dataType: "json",
url: "myurl",
data: JSON.stringify({
"id": id
}),
success: function (Response) {
jQuery("#large-indicator").css("display", "none");
var contentType = "application/pdf";
var folderpath = cordova.file.externalRootDirectory;
if (folderpath == null)
folderpath = cordova.file.dataDirectory
var filename = id + ".pdf";
savebase64AsPDF(folderpath, filename, Response.value, contentType);
},
error: function (Response) {
jQuery("#large-indicator").css("display", "none");
var mex = Response["responseText"];
alert(mex);
}
});
}

这就是我在Android和IOS上取得的成就。干杯！！

使用此插件

<plugin name="cordova-plugin-inappbrowser" />
<plugin name="cordova-plugin-file"/>
<plugin name="cordova-plugin-file-transfer"/>
<plugin spec="https://github.com/tectronik/cordova-plugin-file-opener2-tectronik.git"/>

适合您的工作代码。

var blob = b64toBlob("base64 string here", 'application/pdf');
var pathFile = "";
var fileName ='PdfName.pdf';
var contentFile = blob;
if (ionic.Platform.isIOS()) {
var pathFile = cordova.file.documentsDirectory
} else {
var pathFile = cordova.file.externalRootDirectory
}
$cordovaFile.writeFile(pathFile, fileName, contentFile, true)
.then(function(success) {
$scope.filePath=pathFile + fileName;
// console.log("File saved on internal storage location," + pathFile + fileName);
if (ionic.Platform.isAndroid()) {
$cordovaFileOpener2.open($scope.filePath,
'application/pdf'
).then(function() {
// file opened successfully
// alert(' file opened successfully')
}, function(err) {
alert('An error occurred '+err);
});
}else{
var ref = cordova.InAppBrowser.open(data, '_blank', 
'location=no,toolbar=yes');
}    
}, function(error) {
}); 
function b64toBlob(b64Data, contentType, sliceSize) {
contentType = contentType || '';
sliceSize = sliceSize || 512;
b64Data = b64Data.replace(/^[^,]+,/, '');
b64Data = b64Data.replace(/s/g, '');
var byteCharacters = atob(b64Data);
var byteArrays = [];
for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
var slice = byteCharacters.slice(offset, offset + sliceSize);
var byteNumbers = new Array(slice.length);
for (var i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
var byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
var blob = new Blob(byteArrays, {
type: contentType
});
// return byteCharacters;
return blob;
}

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