我正在构建一个用于壁纸的离子应用程序。
在应用程序中,显示了存储在 www/assets/img 中的图像。我在下面构建了 2 个按钮,用于将显示的图像下载和检索到移动设备内存。
当我单击下载按钮时,会显示一个对话框,显示“下载成功!Pug.jpg 已成功下载到:文件路径”。但是当我检查手机内存时,没有这样的文件。另外,当我单击“检索”按钮时,它会显示对话框显示“文件检索成功!Pug.jpg 已成功检索自:文件路径”,即使手机内存中不存在该文件。
这是 home.ts 代码
import {Component} from '@angular/core';
import {NavController, Platform, AlertController} from 'ionic-angular';
import {Transfer, TransferObject} from '@ionic-native/transfer';
import {File} from '@ionic-native/file';
declare var cordova: any;
@Component({
selector: 'page-home',
templateUrl: 'home.html',
providers: [Transfer, TransferObject, File]
})
export class HomePage {
storageDirectory: string = '';
constructor(public navCtrl: NavController, public platform: Platform, private transfer: Transfer, private file: File, public alertCtrl: AlertController) {
this.platform.ready().then(() => {
// make sure this is on a device, not an emulation (e.g. chrome tools device mode)
if(!this.platform.is('cordova')) {
return false;
}
if (this.platform.is('ios')) {
this.storageDirectory = cordova.file.documentsDirectory;
}
else if(this.platform.is('android')) {
this.storageDirectory = cordova.file.dataDirectory;
}
else {
// exit otherwise, but you could add further types here e.g. Windows
return false;
}
});
}
downloadImage(image) {
this.platform.ready().then(() => {
const fileTransfer: TransferObject = this.transfer.create();
const imageLocation = `${cordova.file.applicationDirectory}www/assets/img/${image}`;
fileTransfer.download(imageLocation, this.storageDirectory + image).then((entry) => {
const alertSuccess = this.alertCtrl.create({
title: `Download Succeeded!`,
subTitle: `${image} was successfully downloaded to: ${entry.toURL()}`,
buttons: ['Ok']
});
alertSuccess.present();
}, (error) => {
const alertFailure = this.alertCtrl.create({
title: `Download Failed!`,
subTitle: `${image} was not successfully downloaded. Error code: ${error.code}`,
buttons: ['Ok']
});
alertFailure.present();
});
});
}
retrieveImage(image) {
this.file.checkFile(this.storageDirectory, image)
.then(() => {
const alertSuccess = this.alertCtrl.create({
title: `File retrieval Succeeded!`,
subTitle: `${image} was successfully retrieved from: ${this.storageDirectory}`,
buttons: ['Ok']
});
return alertSuccess.present();
})
.catch((err) => {
const alertFailure = this.alertCtrl.create({
title: `File retrieval Failed!`,
subTitle: `${image} was not successfully retrieved. Error Code: ${err.code}`,
buttons: ['Ok']
});
return alertFailure.present();
});
}
}
这是home.html代码
<ion-header>
<ion-navbar>
<ion-title>
File Transfer Example
</ion-title>
</ion-navbar>
</ion-header>
<ion-content padding>
<ion-card>
<ion-card-header>
Ionic 3 File Transfer Example
</ion-card-header>
<ion-card-content>
<img src="assets/img/pug.jpg" alt="Cute Pug">
<button ion-button (click)="downloadImage('pug.jpg')" color="secondary">Download image</button>
<button ion-button (click)="retrieveImage('pug.jpg')" color="secondary">Retrieve downloaded image</button>
</ion-card-content>
</ion-card>
</ion-content>
我基于此构建了这个离子应用程序Github 代码示例 https://github.com/dsgriffin/ionic-3-file-transfer-example
我实际上希望离子应用程序首先在内部存储器中创建一个文件夹(应用程序命名的文件夹)并将所有图像放在那里。这样用户就可以访问该文件夹中的文件。例如,如果应用程序名称是“Appsample”,那么所有图像都应该在内存中的 Appsample 文件夹。
我如何才能实现上述目的?
Thanks.