我是Angular的初学者，我想知道如何创建Angular 5文件上传部分，我试图找到任何教程或文档，但我在任何地方都看不到任何东西。对此有什么想法吗?我尝试了ng4-files，但它不适用于Angular 5
当前回答
create-profile.html
<body>
<h1 class="font-weight-bold" >Create Advertistment</h1>
<hr />
<form [formGroup]="form" (submit)="onSubmit()">
<div>
<label class="font-weight-bold">Insert Subject name</label>
<br>
<input formControlName="name" type="text" placeholder="Enter name..." />
</div>
<div>
<br>
<label class="font-weight-bold">Select the Advertistment</label>
<br>
<input (change)="onFileSelect($event)" type="file" />
</div>
<br>
<!--<div *ngIf="imageData">
<img [src]="imageData" [alt]="form.value.name" />
</div>-->
<div>
<label class="font-weight-bold">Upload the Advertistment</label>
<br>
<button type="submit" class="btn btn-success" >Upload Advertistment</button>
</div>
</form>
</body>
create-profile.ts
import { Component, OnInit } from "@angular/core";
import { FormGroup, FormControl } from "@angular/forms";
import { Profile } from "../../models/Profile";
import { ProfileService } from "src/app/services/profile.service";
@Component({
selector: "app-create-profile",
templateUrl: "./create-profile.component.html",
styleUrls: ["./create-profile.component.css"],
})
export class CreateProfileComponent implements OnInit {
form: FormGroup;
profile: Profile;
imageData: string;
constructor(private profileService: ProfileService) {}
ngOnInit(): void {
this.form = new FormGroup({
name: new FormControl(null),
image: new FormControl(null),
});
}
onFileSelect(event: Event) {
const file = (event.target as HTMLInputElement).files[0];
this.form.patchValue({ image: file });
const allowedMimeTypes = ["image/png", "image/jpeg", "image/jpg"];
if (file && allowedMimeTypes.includes(file.type)) {
const reader = new FileReader();
reader.onload = () => {
this.imageData = reader.result as string;
};
reader.readAsDataURL(file);
}
}
onSubmit() {
this.profileService.addProfile(this.form.value.name, this.form.value.image);
this.form.reset();
this.imageData = null;
}
}
profile.service.ts
import { Injectable } from "@angular/core";
import { HttpClient } from "@angular/common/http";
import { map } from "rxjs/operators";
import { Profile } from "../models/Profile";
import { Subject } from "rxjs";
@Injectable({
providedIn: "root",
})
export class ProfileService {
private profiles: Profile[] = [];
private profiles$ = new Subject<Profile[]>();
readonly url = "http://localhost:3000/api/profiles";
constructor(private http: HttpClient) {}
getProfiles() {
this.http
.get<{ profiles: Profile[] }>(this.url)
.pipe(
map((profileData) => {
return profileData.profiles;
})
)
.subscribe((profiles) => {
this.profiles = profiles;
this.profiles$.next(this.profiles);
});
}
getProfilesStream() {
return this.profiles$.asObservable();
}
addProfile(name: string, image: File): void {
const profileData = new FormData();
profileData.append("name", name);
profileData.append("image", image, name);
this.http
.post<{ profile: Profile }>(this.url, profileData)
.subscribe((profileData) => {
const profile: Profile = {
_id: profileData.profile._id,
name: name,
imagePath: profileData.profile.imagePath,
};
this.profiles.push(profile);
this.profiles$.next(this.profiles);
});
}
}
Profile.ts
export interface Profile {
_id: string;
name: string;
imagePath: string;
}
其他回答
就我个人而言，我使用ngx-material-file-input作为前端，Firebase作为后端。更准确地说，后端是与Cloud Firestore结合的Cloud Storage for Firebase。下面是一个示例，它限制文件不大于20 MB，并且只接受某些文件扩展名。我还使用Cloud Firestore来存储上传文件的链接，但你可以跳过这个。
contact.component.html
<mat-form-field>
<!--
Accept only files in the following format: .doc, .docx, .jpg, .jpeg, .pdf, .png, .xls, .xlsx. However, this is easy to bypass, Cloud Storage rules has been set up on the back-end side.
-->
<ngx-mat-file-input
[accept]="[
'.doc',
'.docx',
'.jpg',
'.jpeg',
'.pdf',
'.png',
'.xls',
'.xlsx'
]"
(change)="uploadFile($event)"
formControlName="fileUploader"
multiple
aria-label="Here you can add additional files about your project, which can be helpeful for us."
placeholder="Additional files"
title="Additional files"
type="file"
>
</ngx-mat-file-input>
<mat-icon matSuffix>folder</mat-icon>
<mat-hint
>Accepted formats: DOC, DOCX, JPG, JPEG, PDF, PNG, XLS and XLSX,
maximum files upload size: 20 MB.
</mat-hint>
<!--
Non-null assertion operators are required to let know the compiler that this value is not empty and exists.
-->
<mat-error
*ngIf="contactForm.get('fileUploader')!.hasError('maxContentSize')"
>
This size is too large,
<strong
>maximum acceptable upload size is
{{
contactForm.get('fileUploader')?.getError('maxContentSize')
.maxSize | byteFormat
}}</strong
>
(uploaded size:
{{
contactForm.get('fileUploader')?.getError('maxContentSize')
.actualSize | byteFormat
}}).
</mat-error>
</mat-form-field>
ts(大小验证器部分)
import { FileValidator } from 'ngx-material-file-input';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
/**
* @constructor
* @description Creates a new instance of this component.
* @param {formBuilder} - an abstraction class object to create a form group control for the contact form.
*/
constructor(
private angularFirestore: AngularFirestore,
private angularFireStorage: AngularFireStorage,
private formBuilder: FormBuilder
) {}
public maxFileSize = 20971520;
public contactForm: FormGroup = this.formBuilder.group({
fileUploader: [
'',
Validators.compose([
FileValidator.maxContentSize(this.maxFileSize),
Validators.maxLength(512),
Validators.minLength(2)
])
]
})
ts(文件上传器部分)
import { AngularFirestore } from '@angular/fire/firestore';
import {
AngularFireStorage,
AngularFireStorageReference,
AngularFireUploadTask
} from '@angular/fire/storage';
import { catchError, finalize } from 'rxjs/operators';
import { throwError } from 'rxjs';
public downloadURL: string[] = [];
/**
* @description Upload additional files to Cloud Firestore and get URL to the files.
* @param {event} - object of sent files.
* @returns {void}
*/
public uploadFile(event: any): void {
// Iterate through all uploaded files.
for (let i = 0; i < event.target.files.length; i++) {
const randomId = Math.random()
.toString(36)
.substring(2); // Create random ID, so the same file names can be uploaded to Cloud Firestore.
const file = event.target.files[i]; // Get each uploaded file.
// Get file reference.
const fileRef: AngularFireStorageReference = this.angularFireStorage.ref(
randomId
);
// Create upload task.
const task: AngularFireUploadTask = this.angularFireStorage.upload(
randomId,
file
);
// Upload file to Cloud Firestore.
task
.snapshotChanges()
.pipe(
finalize(() => {
fileRef.getDownloadURL().subscribe((downloadURL: string) => {
this.angularFirestore
.collection(process.env.FIRESTORE_COLLECTION_FILES!) // Non-null assertion operator is required to let know the compiler that this value is not empty and exists.
.add({ downloadURL: downloadURL });
this.downloadURL.push(downloadURL);
});
}),
catchError((error: any) => {
return throwError(error);
})
)
.subscribe();
}
}
storage.rules
rules_version = '2';
service firebase.storage {
match /b/{bucket}/o {
match /{allPaths=**} {
allow read; // Required in order to send this as attachment.
// Allow write files Firebase Storage, only if:
// 1) File is no more than 20MB
// 2) Content type is in one of the following formats: .doc, .docx, .jpg, .jpeg, .pdf, .png, .xls, .xlsx.
allow write: if request.resource.size <= 20 * 1024 * 1024
&& (request.resource.contentType.matches('application/msword')
|| request.resource.contentType.matches('application/vnd.openxmlformats-officedocument.wordprocessingml.document')
|| request.resource.contentType.matches('image/jpg')
|| request.resource.contentType.matches('image/jpeg')
|| request.resource.contentType.matches('application/pdf')
|| request.resource.contentType.matches('image/png')
|| request.resource.contentType.matches('application/vnd.ms-excel')
|| request.resource.contentType.matches('application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'))
}
}
}
在Angular 7/8/9中
来源链接
使用自举表单
<form>
<div class="form-group">
<fieldset class="form-group">
<label>Upload Logo</label>
{{imageError}}
<div class="custom-file fileInputProfileWrap">
<input type="file" (change)="fileChangeEvent($event)" class="fileInputProfile">
<div class="img-space">
<ng-container *ngIf="isImageSaved; else elseTemplate">
<img [src]="cardImageBase64" />
</ng-container>
<ng-template #elseTemplate>
<img src="./../../assets/placeholder.png" class="img-responsive">
</ng-template>
</div>
</div>
</fieldset>
</div>
<a class="btn btn-danger" (click)="removeImage()" *ngIf="isImageSaved">Remove</a>
</form>
在组件类中
fileChangeEvent(fileInput: any) {
this.imageError = null;
if (fileInput.target.files && fileInput.target.files[0]) {
// Size Filter Bytes
const max_size = 20971520;
const allowed_types = ['image/png', 'image/jpeg'];
const max_height = 15200;
const max_width = 25600;
if (fileInput.target.files[0].size > max_size) {
this.imageError =
'Maximum size allowed is ' + max_size / 1000 + 'Mb';
return false;
}
if (!_.includes(allowed_types, fileInput.target.files[0].type)) {
this.imageError = 'Only Images are allowed ( JPG | PNG )';
return false;
}
const reader = new FileReader();
reader.onload = (e: any) => {
const image = new Image();
image.src = e.target.result;
image.onload = rs => {
const img_height = rs.currentTarget['height'];
const img_width = rs.currentTarget['width'];
console.log(img_height, img_width);
if (img_height > max_height && img_width > max_width) {
this.imageError =
'Maximum dimentions allowed ' +
max_height +
'*' +
max_width +
'px';
return false;
} else {
const imgBase64Path = e.target.result;
this.cardImageBase64 = imgBase64Path;
this.isImageSaved = true;
// this.previewImagePath = imgBase64Path;
}
};
};
reader.readAsDataURL(fileInput.target.files[0]);
}
}
removeImage() {
this.cardImageBase64 = null;
this.isImageSaved = false;
}
我使用的是Angular 5.2.11， 我喜欢Gregor Doroschenko提供的解决方案，但是我注意到上传的文件是零字节的，我必须做一个小小的改变才能让它为我工作。
postFile(fileToUpload: File): Observable<boolean> {
const endpoint = 'your-destination-url';
return this.httpClient
.post(endpoint, fileToUpload, { headers: yourHeadersConfig })
.map(() => { return true; })
.catch((e) => this.handleError(e));
}
下面几行(formData)对我不起作用。
const formData: FormData = new FormData();
formData.append('fileKey', fileToUpload, fileToUpload.name);
https://github.com/amitrke/ngrke/blob/master/src/app/services/fileupload.service.ts
非常简单和最快的方法是使用ng2-file-upload。
通过npm安装ng2-file-upload。NPM I ng2-file-upload——保存
首先在模块中导入模块。
import { FileUploadModule } from 'ng2-file-upload';
Add it to [imports] under @NgModule:
imports: [ ... FileUploadModule, ... ]
标记:
<input ng2FileSelect type="file" accept=".xml" [uploader]="uploader"/>
在你的组件中:
import { FileUploader } from 'ng2-file-upload';
...
uploader: FileUploader = new FileUploader({ url: "api/your_upload", removeAfterUpload: false, autoUpload: true });
这是最简单的用法。要知道所有的权力，这看到演示
使用Angular和nodejs上传文件的完整示例(express)
HTML代码
<div class="form-group">
<label for="file">Choose File</label><br/>
<input type="file" id="file" (change)="uploadFile($event.target.files)" multiple>
</div>
TS组件代码
uploadFile(files) {
console.log('files', files)
var formData = new FormData();
for(let i =0; i < files.length; i++){
formData.append("files", files[i], files[i]['name']);
}
this.httpService.httpPost('/fileUpload', formData)
.subscribe((response) => {
console.log('response', response)
},
(error) => {
console.log('error in fileupload', error)
})
}
Node Js代码
上传火灾控制器
function start(req, res) {
fileUploadService.fileUpload(req, res)
.then(fileUploadServiceResponse => {
res.status(200).send(fileUploadServiceResponse)
})
.catch(error => {
res.status(400).send(error)
})
}
module.exports.start = start
使用multer上传服务
const multer = require('multer') // import library
const moment = require('moment')
const q = require('q')
const _ = require('underscore')
const fs = require('fs')
const dir = './public'
/** Store file on local folder */
let storage = multer.diskStorage({
destination: function (req, file, cb) {
cb(null, 'public')
},
filename: function (req, file, cb) {
let date = moment(moment.now()).format('YYYYMMDDHHMMSS')
cb(null, date + '_' + file.originalname.replace(/-/g, '_').replace(/ /g, '_'))
}
})
/** Upload files */
let upload = multer({ storage: storage }).array('files')
/** Exports fileUpload function */
module.exports = {
fileUpload: function (req, res) {
let deferred = q.defer()
/** Create dir if not exist */
if (!fs.existsSync(dir)) {
fs.mkdirSync(dir)
console.log(`\n\n ${dir} dose not exist, hence created \n\n`)
}
upload(req, res, function (err) {
if (req && (_.isEmpty(req.files))) {
deferred.resolve({ status: 200, message: 'File not attached', data: [] })
} else {
if (err) {
deferred.reject({ status: 400, message: 'error', data: err })
} else {
deferred.resolve({
status: 200,
message: 'File attached',
filename: _.pluck(req.files,
'filename'),
data: req.files
})
}
}
})
return deferred.promise
}
}
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