Angular文件上传

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

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

2018-10-08 20:16:30

其他回答

试试这个

安装

npm install primeng --save

进口

import {FileUploadModule} from 'primeng/primeng';

Html

<p-fileUpload name="myfile[]" url="./upload.php" multiple="multiple"
    accept="image/*" auto="auto"></p-fileUpload>

2017-12-22 05:55:20

在我的情况下，我使用http拦截器，事情是，默认情况下，我的http拦截器设置内容类型头为应用程序/json，但对于文件上传，我使用multer库。稍微改变一下我的http。interceptor定义，如果请求体是FormData，它会删除头，不触及访问令牌。下面是一部分代码，它让我很开心。

if (request.body instanceof FormData) {
  request = request.clone({ headers: request.headers.delete('Content-Type', 'application/json') });
}

if (request.body instanceof FormData) {
  request = request.clone({ headers: request.headers.delete('Accept', 'application/json')});
}

2021-02-03 13:19:34

下面是一个上传文件到api的例子:

步骤1:HTML模板

定义文件类型的简单输入标记。为(change)-event添加一个处理选择文件的函数。

<div class="form-group">
    <label for="file">Choose File</label>
    <input type="file"
           id="file"
           (change)="handleFileInput($event.target.files)">
</div>

步骤2:在TypeScript中处理上传

为所选文件定义一个默认变量。

fileToUpload: File | null = null;

创建你在(change)-event中使用的函数:

handleFileInput(files: FileList) {
    this.fileToUpload = files.item(0);
}

如果你想处理多文件选择，那么你可以遍历这个文件数组。

现在通过调用file-upload.service创建文件上传函数:

uploadFileToActivity() {
    this.fileUploadService.postFile(this.fileToUpload).subscribe(data => {
      // do something, if upload success
      }, error => {
        console.log(error);
      });
  }

第三步:文件上传服务

通过post方法上传文件，你应该使用FormData，因为这样你可以添加文件到http请求。

postFile(fileToUpload: File): Observable<boolean> {
    const endpoint = 'your-destination-url';
    const formData: FormData = new FormData();
    formData.append('fileKey', fileToUpload, fileToUpload.name);
    return this.httpClient
      .post(endpoint, formData, { headers: yourHeadersConfig })
      .map(() => { return true; })
      .catch((e) => this.handleError(e));
}

所以，这是一个非常简单的工作例子，我每天都在工作中使用。

2017-12-22 08:24:30

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

2018-07-13 15:43:55

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;
}

2021-03-05 17:40:44

Angular文件上传

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