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
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
其他回答
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
通过这种方式,我实现了在项目中上传文件到web API。
我为谁分担关心。
const formData: FormData = new FormData();
formData.append('Image', image, image.name);
formData.append('ComponentId', componentId);
return this.http.post('/api/dashboard/UploadImage', formData);
一步一步
ASP。网上广告
[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表单
<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($event.target.files)" />
<button type="submit" class="btn-large btn-submit" [disabled]="Image.value=='' || !imageForm.valid"><i
class="material-icons">save</i></button>
</div>
</form>
TS文件使用API
OnSubmit(Image) {
this.dashboardService.uploadImage(this.componentId, this.fileToUpload).subscribe(
data => {
console.log('done');
Image.value = null;
this.imageUrl = "/assets/img/logo.png";
}
);
}
服务TS
uploadImage(componentId, image) {
const formData: FormData = new FormData();
formData.append('Image', image, image.name);
formData.append('ComponentId', componentId);
return this.http.post('/api/dashboard/UploadImage', formData);
}
在我的情况下,我使用http拦截器,事情是,默认情况下,我的http拦截器设置内容类型头为应用程序/json,但对于文件上传,我使用multer库。 稍微改变一下我的http。interceptor定义,如果请求体是FormData,它会删除头,不触及访问令牌。 下面是一部分代码,它让我很开心。
if (request.body instanceof FormData) {
request = request.clone({ headers: request.headers.delete('Content-Type', 'application/json') });
}
if (request.body instanceof FormData) {
request = request.clone({ headers: request.headers.delete('Accept', 'application/json')});
}
下面是我上传excel文件的方法: 目录结构:
app
|-----uploadcomponent
|-----uploadcomponent.module.ts
|-----uploadcomponent.html
|-----app.module.ts
|-----app.component.ts
|-----app.service.ts
uploadcomponent.html
<div>
<form [formGroup]="form" (ngSubmit)="onSubmit()">
<input type="file" name="profile" enctype="multipart/form-data" accept=".xlsm,application/msexcel" (change)="onChange($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!
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;
}
推荐文章
- NullInjectorError: AngularFirestore没有提供程序
- 从元组/数组值派生联合类型
- 如何在Angular2中截断文本?
- 如何在Angular2 ngSwitch语句中使用typescript enum值
- Angular CLI错误:serve命令需要在Angular项目中运行,但是找不到项目定义
- 找到合成属性@panelState。请在您的应用程序中包含“BrowserAnimationsModule”或“NoopAnimationsModule”。
- 在Angular中上传文件?
- 模板驱动表单和响应式表单之间的实际区别是什么?
- Angular 2+和debounce
- 在TypeScript箭头函数中指定返回类型
- 如何使用jQuery与TypeScript
- 如何以及在哪里使用::ng-deep?
- 禁用在角材质对话框区域外单击以关闭对话框(angular 4.0+版本)
- Angular 2模板中的标签是什么意思?
- Typescript接口-可能使“一个或另一个”属性要求?