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。
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