角度文件上傳

Question

我是 Angular 的初學者，我想知道如何創建 Angular 5文件上傳部分，我試圖找到任何教程或文檔，但我在任何地方都看不到任何東西。 對此有什么想法嗎？ 我嘗試過ng4-files但它不適用於 Angular 5

Answer 1

這是將文件上傳到 api 的工作示例：

第 1 步：HTML 模板（file-upload.component.html）

定義類型為file簡單輸入標簽。 向(change) -event 添加一個函數來處理選擇文件。

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

第 2 步：在 TypeScript 中上傳處理 (file-upload.component.ts)

為所選文件定義默認變量。

fileToUpload: File | null = null;

創建您在文件輸入標簽的(change) -event 中使用的函數：

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

如果要處理多文件選擇，則可以遍歷此文件數組。

現在通過調用 file-upload.service 來創建文件上傳功能：

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

第三步：文件上傳服務（file-upload.service.ts）

通過 POST 方法上傳文件，您應該使用FormData ，因為這樣您就可以將文件添加到 http 請求。

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，這是一個非常簡單的工作示例，我每天都在工作中使用它。

Answer 2

通過這種方式，我在項目中實現了將文件上傳到 Web API。

我分擔為誰關心。

const formData: FormData = new FormData();
formData.append('Image', image, image.name);
formData.append('ComponentId', componentId);
return this.http.post('/api/dashboard/UploadImage', formData);

一步步

ASP.NET Web API

[HttpPost]
[Route("api/dashboard/UploadImage")]
public HttpResponseMessage UploadImage() 
{
    string imageName = null;
    var httpRequest = HttpContext.Current.Request;
    //Upload Image
    var postedFile = httpRequest.Files["Image"];
    //Create custom filename
    if (postedFile != null)
    {
        imageName = new String(Path.GetFileNameWithoutExtension(postedFile.FileName).Take(10).ToArray()).Replace(" ", "-");
        imageName = imageName + DateTime.Now.ToString("yymmssfff") + Path.GetExtension(postedFile.FileName);
        var filePath = HttpContext.Current.Server.MapPath("~/Images/" + imageName);
        postedFile.SaveAs(filePath);
    }
}

HTML 表單

<form #imageForm=ngForm (ngSubmit)="OnSubmit(Image)">

    <img [src]="imageUrl" class="imgArea">
    <div class="image-upload">
        <label for="file-input">
            <img src="upload.jpg" />
        </label>

        <input id="file-input" #Image type="file" (change)="handleFileInput($event.target.files)" />
        <button type="submit" class="btn-large btn-submit" [disabled]="Image.value=='' || !imageForm.valid"><i
                class="material-icons">save</i></button>
    </div>
</form>

使用 API 的 TS 文件

OnSubmit(Image) {
    this.dashboardService.uploadImage(this.componentId, this.fileToUpload).subscribe(
      data => {
        console.log('done');
        Image.value = null;
        this.imageUrl = "/assets/img/logo.png";
      }
    );
  }

服務TS

uploadImage(componentId, image) {
        const formData: FormData = new FormData();
        formData.append('Image', image, image.name);
        formData.append('ComponentId', componentId);
        return this.http.post('/api/dashboard/UploadImage', formData);
    }

Answer 3

非常簡單快捷的方法是使用ng2-file-upload 。

通過 npm 安裝 ng2-file-upload。 npm i ng2-file-upload --save

首先在您的模塊中導入模塊。

import { FileUploadModule } from 'ng2-file-upload';

Add it to [imports] under @NgModule:
imports: [ ... FileUploadModule, ... ]

標記：

<input ng2FileSelect type="file" accept=".xml" [uploader]="uploader"/>

在您的組件 ts 中：

import { FileUploader } from 'ng2-file-upload';
...
uploader: FileUploader = new FileUploader({ url: "api/your_upload", removeAfterUpload: false, autoUpload: true });

這是最簡單的用法。 要了解此功能的所有功能，請參閱演示

Answer 4

1. HTML

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

    <button type="button" (click)="RequestUpload()">Ok</button>

2. .ts 文件

public formData = new FormData();
ReqJson: any = {};

uploadFiles( file ) {
        console.log( 'file', file )
        for ( let i = 0; i < file.length; i++ ) {
            this.formData.append( "file", file[i], file[i]['name'] );
        }
    }

RequestUpload() {
        this.ReqJson["patientId"] = "12"
        this.ReqJson["requesterName"] = "test1"
        this.ReqJson["requestDate"] = "1/1/2019"
        this.ReqJson["location"] = "INDIA"
        this.formData.append( 'Info', JSON.stringify( this.ReqJson ) )
            this.http.post( '/Request', this.formData )
                .subscribe(( ) => {                 
                });     
    }

3. 后端Spring（java文件）

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

@Controller
public class Request {
    private static String UPLOADED_FOLDER = "c://temp//";

    @PostMapping("/Request")
    @ResponseBody
    public String uploadFile(@RequestParam("file") MultipartFile file, @RequestParam("Info") String Info) {
        System.out.println("Json is" + Info);
        if (file.isEmpty()) {
            return "No file attached";
        }
        try {
            // Get the file and save it somewhere
            byte[] bytes = file.getBytes();
            Path path = Paths.get(UPLOADED_FOLDER + file.getOriginalFilename());
            Files.write(path, bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "Succuss";
    }
}

我們必須在 C 盤創建一個文件夾“temp”，然后這段代碼將在控制台打印 Json 並將上傳的文件保存在創建的文件夾中

Answer 5

首先，您需要在 Angular 項目中設置 HttpClient。

打開src/app/app.module.ts文件，導入HttpClientModule並添加到模塊的imports數組中，如下：

import { BrowserModule } from '@angular/platform-browser';  
import { NgModule } from '@angular/core';
import { AppRoutingModule } from './app-routing.module';  
import { AppComponent } from './app.component';  
import { HttpClientModule } from '@angular/common/http';

@NgModule({  
  declarations: [  
    AppComponent,  
  ],  
  imports: [  
    BrowserModule,  
    AppRoutingModule,  
    HttpClientModule  
  ],  
  providers: [],  
  bootstrap: [AppComponent]  
})  
export class AppModule { }

接下來，生成一個組件：

$ ng generate component home

接下來，生成一個上傳服務：

$ ng generate service upload

接下來，打開 src/app/upload.service.ts 文件如下：

import { HttpClient, HttpEvent, HttpErrorResponse, HttpEventType } from  '@angular/common/http';  
import { map } from  'rxjs/operators';

@Injectable({  
  providedIn: 'root'  
})  
export class UploadService { 
    SERVER_URL: string = "https://file.io/";  
    constructor(private httpClient: HttpClient) { }
    public upload(formData) {

      return this.httpClient.post<any>(this.SERVER_URL, formData, {  
         reportProgress: true,  
         observe: 'events'  
      });  
   }
}

接下來，打開 src/app/home/home.component.ts 文件，並開始添加以下導入：

import { Component, OnInit, ViewChild, ElementRef  } from '@angular/core';
import { HttpEventType, HttpErrorResponse } from '@angular/common/http';
import { of } from 'rxjs';  
import { catchError, map } from 'rxjs/operators';  
import { UploadService } from  '../upload.service';

接下來，定義 fileUpload 和 files 變量並注入 UploadService 如下：

@Component({  
  selector: 'app-home',  
  templateUrl: './home.component.html',  
  styleUrls: ['./home.component.css']  
})  
export class HomeComponent implements OnInit {
    @ViewChild("fileUpload", {static: false}) fileUpload: ElementRef;files  = [];  
    constructor(private uploadService: UploadService) { }

接下來，定義 uploadFile() 方法：

uploadFile(file) {  
    const formData = new FormData();  
    formData.append('file', file.data);  
    file.inProgress = true;  
    this.uploadService.upload(formData).pipe(  
      map(event => {  
        switch (event.type) {  
          case HttpEventType.UploadProgress:  
            file.progress = Math.round(event.loaded * 100 / event.total);  
            break;  
          case HttpEventType.Response:  
            return event;  
        }  
      }),  
      catchError((error: HttpErrorResponse) => {  
        file.inProgress = false;  
        return of(`${file.data.name} upload failed.`);  
      })).subscribe((event: any) => {  
        if (typeof (event) === 'object') {  
          console.log(event.body);  
        }  
      });  
  }

接下來，定義uploadFiles() 方法，該方法可用於上傳多個圖像文件：

private uploadFiles() {  
    this.fileUpload.nativeElement.value = '';  
    this.files.forEach(file => {  
      this.uploadFile(file);  
    });  
}

接下來，定義 onClick() 方法：

onClick() {  
    const fileUpload = this.fileUpload.nativeElement;fileUpload.onchange = () => {  
    for (let index = 0; index < fileUpload.files.length; index++)  
    {  
     const file = fileUpload.files[index];  
     this.files.push({ data: file, inProgress: false, progress: 0});  
    }  
      this.uploadFiles();  
    };  
    fileUpload.click();  
}

接下來，我們需要創建圖片上傳 UI 的 HTML 模板。 打開 src/app/home/home.component.html 文件，添加如下內容：

<div [ngStyle]="{'text-align':center; 'margin-top': 100px;}">
   <button mat-button color="primary" (click)="fileUpload.click()">choose file</button>  
   <button mat-button color="warn" (click)="onClick()">Upload</button>  
   <input [hidden]="true" type="file" #fileUpload id="fileUpload" name="fileUpload" multiple="multiple" accept="image/*" />
</div>

看看這個教程和這篇文章

Answer 6

好的，由於此線程出現在 google 的第一個結果中，並且對於其他有相同問題的用戶，您不必像 trueboroda 所指出的那樣重新啟動輪子，有 ng2-file-upload 庫，它簡化了上傳文件的過程角度為 6 和 7 的文件，您需要做的就是：

安裝最新的 Angular CLI

yarn add global @angular/cli

然后安裝 rx-compat 考慮兼容性問題

npm install rxjs-compat --save

安裝 ng2-file-upload

npm install ng2-file-upload --save

在您的模塊中導入 FileSelectDirective 指令。

import { FileSelectDirective } from 'ng2-file-upload';

Add it to [declarations] under @NgModule:
declarations: [ ... FileSelectDirective , ... ]

在您的組件中

import { FileUploader } from 'ng2-file-upload/ng2-file-upload';
...

export class AppComponent implements OnInit {

   public uploader: FileUploader = new FileUploader({url: URL, itemAlias: 'photo'});
}

模板

<input type="file" name="photo" ng2FileSelect [uploader]="uploader" />

為了更好地理解，您可以查看此鏈接： 如何使用 Angular 6/7 上傳文件

Answer 7

我使用的是 Angular 5.2.11，我喜歡 Gregor Doroschenko 提供的解決方案，但是我注意到上傳的文件是零字節，我不得不做一些小改動才能讓它對我有用。

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));
}

以下幾行（formData）對我不起作用。

const formData: FormData = new FormData();
formData.append('fileKey', fileToUpload, fileToUpload.name);

https://github.com/amitrke/ngrke/blob/master/src/app/services/fileupload.service.ts

Answer 8

就我個人而言，我在前端使用ngx-material-file-input ，后端使用Firebase 。 更准確地說，用於后端的Firebase 的C響亮存儲與 Cloud Firestore 相結合。 下面是一個示例，它限制文件不大於 20 MB，並且只接受某些文件擴展名。 我還使用Cloud Firestore來存儲上傳文件的鏈接，但您可以跳過此步驟。

聯系方式.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>

contact.component.ts （尺寸驗證器部分）

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)
      ])
    ]
})

contact.component.ts （文件上傳部分）

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();
    }
  }

存儲規則

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'))
    }
  }
}

Answer 9

使用 Angular 和 nodejs(express) 上傳文件的完整示例

HTML代碼

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

TS 組件代碼

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)
       })
  }

節點 Js 代碼

文件上傳 API 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上傳服務

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
}
}

Answer 10

這是我上傳excel文件的方法：
目錄結構：

app
|-----uploadcomponent
           |-----uploadcomponent.module.ts
           |-----uploadcomponent.html
|-----app.module.ts
|-----app.component.ts
|-----app.service.ts

上傳組件.html

<div>
   <form [formGroup]="form" (ngSubmit)="onSubmit()">
     <input type="file" name="profile"  enctype="multipart/form-data" accept=".xlsm,application/msexcel" (change)="onChange($event)" />
     <button type="submit">Upload Template</button>
     <button id="delete_button" class="delete_button" type="reset"><i class="fa fa-trash"></i></button> 
   </form>           
</div>

上傳組件.ts

    import { FormBuilder, FormGroup, ReactiveFormsModule } from '@angular/forms';
    import { Component, OnInit } from '@angular/core';
    ....
    export class UploadComponent implements OnInit {
        form: FormGroup;
        constructor(private formBuilder: FormBuilder, private uploadService: AppService) {}
        ngOnInit() {  
            this.form = this.formBuilder.group({
               profile: ['']
            });
        }

        onChange(event) {
            if (event.target.files.length > 0) {
              const file = event.target.files[0];

              this.form.get('profile').setValue(file);
              console.log(this.form.get('profile').value)
            }
        }

        onSubmit() {
           const formData = new FormData();
           formData.append('file', this.form.get('profile').value);

           this.uploadService.upload(formData).subscribe(
             (res) => {
               this.response = res;

               console.log(res);

             },
             (err) => {  
               console.log(err);
             });
         }
    }

應用服務.ts

    upload(formData) {
        const endpoint = this.service_url+'upload/';
        const httpOptions = headers: new HttpHeaders({    <<<< Changes are here
            'Authorization': 'token xxxxxxx'})
        };
        return this.http.post(endpoint, formData, httpOptions);
    }

在后端，我使用 DJango REST 框架。
模型.py

from __future__ import unicode_literals
from django.db import models
from django.db import connection
from django_mysql.models import JSONField, Model
import uuid
import os


def change_filename(instance, filename):
    extension = filename.split('.')[-1]
    file_name = os.path.splitext(filename)[0]
    uuid_name = uuid.uuid4()
    return file_name+"_"+str(uuid_name)+"."+extension

class UploadTemplate (Model):
    id = models.AutoField(primary_key=True)
    file = models.FileField(blank=False, null=False, upload_to=change_filename)

    def __str__(self):
        return str(self.file.name)

視圖.py。

class UploadView(APIView):
    serializer_class = UploadSerializer
    parser_classes = [MultiPartParser]       

    def get_queryset(self):
        queryset = UploadTemplate.objects.all()
        return queryset

    def post(self, request, *args, **kwargs):
        file_serializer = UploadSerializer(data=request.data)
        status = None
        message = None
        if file_serializer.is_valid():
            file_serializer.save()
            status = "Success"
            message = "Success"
        else:
            status = "Failure"
            message = "Failure!"
        content = {'status': status, 'message': message}
        return Response(content)

序列化器.py。

from uploadtemplate.models import UploadTemplate
from rest_framework import serializers

class UploadSerializer(serializers.ModelSerializer):
    class Meta:
        model = UploadTemplate
        fields = '__all__'   

網址.py。

router.register(r'uploadtemplate', uploadtemplateviews.UploadTemplateView, 
    base_name='UploadTemplate')
urlpatterns = [
    ....
    url(r'upload/', uploadtemplateviews.UploadTemplateView.as_view()),
] + static(settings.STATIC_URL, document_root=settings.STATIC_ROOT)

if settings.DEBUG:
    urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

MEDIA_URL 和 MEDIA_ROOT 在項目的 settings.py 中定義。

謝謝！

Answer 11

在Angular 7/8/9

源鏈接

使用Bootstrap 表單

<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>

在組件類中

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;
}

Answer 12

嘗試這個

安裝

npm install primeng --save

進口

import {FileUploadModule} from 'primeng/primeng';

html

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

Answer 13

就我而言，我使用的是 http 攔截器，默認情況下，我的 http 攔截器將content-type標頭設置為application/json ，但對於文件上傳，我使用的是multer庫。 所以一點點改變我的 http.interceptor 定義如果請求正文是 FormData 它刪除標頭並且不接觸訪問令牌。 這是代碼的一部分，這讓我很開心。

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')});
}

Answer 14

創建-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>

創建-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);
      });
  }
}

配置文件.ts

export interface Profile {
  _id: string;
  name: string;
  imagePath: string;
}