Upload image to Web Api 2 Using angular 5

Question

I reviewed a few questions and answers, but could not solve my problem. My code is as follows:

HTML

 <input type="file" id="file" accept="image/*" name="File" (change)="handleFileInput($event.target.files)">
 <button type="button" mat-raised-button color="primary" (click)="uploadFileToActivity()">Upload</button>

Component

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

  uploadFileToActivity() {

    this._dishAddService.postFile(this.fileToUpload).subscribe(data => {

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

Service

 postFile(fileToUpload: File): Observable<boolean> {
    const formData: FormData = new FormData();
    formData.append('fileKey', fileToUpload, fileToUpload.name);
    let headers = new Headers({ 'Content-Type': 'application/json' });    
    headers.append('Content-Type', 'multipart/form-data');

    let options = new RequestOptions({ headers: headers, method: 'post' });
    return this.http.post(this.httpRequestUrl + 'api/dish/UploadDishImage', formData, options)
      .map(
        (response => response.json()))
      .catch(CommonFunctionService.handleError);
  }

API

   [HttpPost]
    [ActionName("UploadDishImage")]
    public HttpResponseMessage UploadJsonFile()
    {
        HttpResponseMessage response = new HttpResponseMessage();
        var httpRequest = HttpContext.Current.Request;
        if (httpRequest.Files.Count > 0)
        {
            foreach (string file in httpRequest.Files)
            {
                var postedFile = httpRequest.Files[file];
                var filePath = HttpContext.Current.Server.MapPath("~/UploadFile/" + postedFile.FileName);
                postedFile.SaveAs(filePath);
            }
        }
        return response;
    }

When the request falls into the API, the number of files is 0. I spent two whole days to figure out what was going wrong, but also unable to figure out what was wrong. I don’t think that something is wrong with the code, because for another it works. I took the code from another accepted SO answer. Can someone help me figure out what could go wrong?

Answer 1

FileUpload is very simple with angular. You can use this description here or follow my steps.

, . $event.target.files .

<input type="file" (change)="upload($event.target.files)">

files.service.ts ( , - ), , , .

import { FilesService } from 'PATHTO/files.service';
[...]
contructor(private filesService: FilesService) { }

, files.item formData​​p >

upload(files: FileList) {
  const file = files.item(0);

  this.filesService.upload(file).subscribe(
    res => /* Place your success actions here */,
    error => /* Place your error actions here */
  );
}

, url URL . , files.service.ts :

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

import { Observable } from 'rxjs/Observable';
import { environment } from 'PATHTO/environments/environment';

@Injectable()
export class FilesService {

  constructor(private http: HttpClient) { }

  upload(file: File): Observable<Object> {
    const formData: FormData = new FormData();
    formData.append('avatar', file, file.name);

    return this.http.post(`${environment.url}avatar.php`, formData);
  }
}

, php- $_ FILES. Asp.net, , .

, , ! .

Answer 2

, -API .

, .

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

[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

<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>

TS API

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

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);
    }