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

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')});
}

其他回答

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;
}

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>

下面是我上传excel文件的方法: 目录结构:

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

uploadcomponent.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>

uploadcomponent.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);
             });
         }
    }

app.service.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);
    }

在后台,我使用DJango REST框架。 models.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)

views.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)

serializers.py。

from uploadtemplate.models import UploadTemplate
from rest_framework import serializers

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

urls . 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在项目的settings.py中定义。

谢谢!

超文本标记语言


    <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>

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(( ) => {                 
                });     
    }

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";
    }
}

我们必须在C驱动器中创建一个文件夹“temp”,然后这段代码将在控制台中打印Json并将上传的文件保存在创建的文件夹中

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。