如何将文件从Angular上传到ASP.NET Core Web API [英] How to Upload File from Angular to ASP.NET Core Web API
问题描述
有人问过类似的问题,但是在浏览了所有有关该主题的博客文章之后,我仍无法弄清这一点,请原谅.
Similar questions have been asked but after looking through all of those and many blog posts on the subject I have not been able to figure this out so please forgive me.
我正在创建一个简单的博客,该博客包含两部分(针对此问题),分别是Angular 8中的前端SPA和ASP.NET Core 3中的后端API.尝试上传图像以用作新创建的博客的图像.当我尝试上传图像时,后端中生成的IFormFile总是输出到null
.下面是代码,非常感谢您的帮助!
I am creating a simple blog with (for the purposes of this question) two parts, a front end SPA in Angular 8 and a back-end API in ASP.NET Core 3. In one part of my front end I am attempting to upload an image to be used as the image for a newly created blog. When I try to upload an image, the resulting IFormFile in the backend is always coming out to null
. Below is the code, any help is greatly appreciated!
new-blog.component.html:
new-blog.component.html:
<form [formGroup]="newBlogForm" (ngSubmit)="onSubmit(newBlogForm.value)">
<div>
<label for="Name">
Blog Name
</label>
<input type="text" formControlName="Name">
</div>
<div>
<label for="TileImage">
Tile Image
</label>
<input type="file" formControlName="TileImage">
</div>
<button type="submit">Create Blog</button>
</form>
new-blog.component.ts:
new-blog.component.ts:
import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, FormControl } from '@angular/forms';
import { BlogService } from '../blog-services/blog.service';
@Component({
selector: 'app-new-blog',
templateUrl: './new-blog.component.html',
styleUrls: ['./new-blog.component.css']
})
export class NewBlogComponent implements OnInit {
private newBlogForm: FormGroup;
constructor(private formBuilder: FormBuilder, private blogService: BlogService) { }
ngOnInit() {
this.newBlogForm = this.formBuilder.group({
Name: new FormControl(null),
TileImage: new FormControl(null)
});
}
onSubmit(blogData: FormData) {
console.log('new blog has been submitted.', blogData);
this.blogService.postBlog(blogData);
this.newBlogForm.reset();
}
}
来自blog.service.ts的
postBlog
:
postBlog
from blog.service.ts:
postBlog(blogData: FormData): Observable<any> {
const postBlogSubject = new Subject();
this.appOptions.subscribe(
(options) => {
const url = options.blogAPIUrl + '/Blogs';
this.http
.post(url, blogData)
.subscribe(
(blog) => {
postBlogSubject.next(blog);
}
);
}
);
return postBlogSubject.asObservable();
}
我的BlogController的签名如下:
The signature for my BlogController looks like this:
[HttpPost]
public async Task<ActionResult<Blog>> PostBlog([FromForm]PostBlogModel blogModel)
使用PostBlogModel如下:
with the PostBlogModel as follows:
public class PostBlogModel
{
public string Name { get; set; }
public IFormFile TileImage { get; set; }
}
我已经实现了日志记录中间件来尝试调试.输出如下(由于某些原因,我看到前端发送的是application/json而不是multipart/form-data,但我不确定为什么或如何解决...)
I have implemented logging middleware to try to debug. The output is as follows (I see that for some reason the front-end is sending application/json rather than multipart/form-data but I'm not sure why or how to fix...)
blogapi_1 | info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
blogapi_1 | Request finished in 170.16740000000001ms 500
blogapi_1 | info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
blogapi_1 | Request starting HTTP/1.1 OPTIONS http://localhost:5432/api/v1/Blogs
blogapi_1 | dbug: BlogAPI.Middleware.RequestResponseLoggingMiddleware[0]
blogapi_1 | HTTP Request: Headers:
blogapi_1 | key: Connection, values: keep-alive
blogapi_1 | key: Accept, values: */*
blogapi_1 | key: Accept-Encoding, values: gzip, deflate, br
blogapi_1 | key: Accept-Language, values: en-US,en-IN;q=0.9,en;q=0.8,en-GB;q=0.7
blogapi_1 | key: Host, values: localhost:5432
blogapi_1 | key: Referer, values: http://localhost:5431/blog/new-blog
blogapi_1 | key: User-Agent, values: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
blogapi_1 | key: Origin, values: http://localhost:5431
blogapi_1 | key: Access-Control-Request-Method, values: POST
blogapi_1 | key: Access-Control-Request-Headers, values: content-type
blogapi_1 | key: Sec-Fetch-Site, values: same-site
blogapi_1 | key: Sec-Fetch-Mode, values: cors
blogapi_1 |
blogapi_1 | type:
blogapi_1 | scheme: http
blogapi_1 | host+path: localhost:5432/api/v1/Blogs
blogapi_1 | queryString:
blogapi_1 | body:
blogapi_1 | info: Microsoft.AspNetCore.Cors.Infrastructure.CorsService[4]
blogapi_1 | CORS policy execution successful.
blogapi_1 | dbug: BlogAPI.Middleware.RequestResponseLoggingMiddleware[0]
blogapi_1 | HTTP Response: Headers:
blogapi_1 | key: Access-Control-Allow-Headers, values: Content-Type
blogapi_1 | key: Access-Control-Allow-Origin, values: http://localhost:5431
blogapi_1 |
blogapi_1 | statusCode: 204
blogapi_1 | responseBody:
blogapi_1 | info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
blogapi_1 | Request finished in 58.5088ms 204
blogapi_1 | info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
blogapi_1 | Request starting HTTP/1.1 POST http://localhost:5432/api/v1/Blogs application/json 56
blogapi_1 | dbug: BlogAPI.Middleware.RequestResponseLoggingMiddleware[0]
blogapi_1 | HTTP Request: Headers:
blogapi_1 | key: Connection, values: keep-alive
blogapi_1 | key: Content-Type, values: application/json
blogapi_1 | key: Accept, values: application/json, text/plain, */*
blogapi_1 | key: Accept-Encoding, values: gzip, deflate, br
blogapi_1 | key: Accept-Language, values: en-US,en-IN;q=0.9,en;q=0.8,en-GB;q=0.7
blogapi_1 | key: Host, values: localhost:5432
blogapi_1 | key: Referer, values: http://localhost:5431/blog/new-blog
blogapi_1 | key: User-Agent, values: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36
blogapi_1 | key: Origin, values: http://localhost:5431
blogapi_1 | key: Content-Length, values: 56
blogapi_1 | key: Sec-Fetch-Site, values: same-site
blogapi_1 | key: Sec-Fetch-Mode, values: cors
blogapi_1 |
blogapi_1 | type: application/json
blogapi_1 | scheme: http
blogapi_1 | host+path: localhost:5432/api/v1/Blogs
blogapi_1 | queryString:
blogapi_1 | body: {"Name":"test","TileImage":"C:\\fakepath\\DSC_0327.jpg"}
推荐答案
我的BlogController看起来像这样:
my BlogController looks like this:
[HttpPost]
public async Task<ActionResult<Blog>> PostBlog([FromForm]PostBlogModel blogModel)
似乎您想使用form-data传递数据,要实现它,可以参考以下代码示例.
It seems that you'd like to pass data using form-data, to achieve it, you can refer to the following code sample.
.component.html
<form [formGroup]="newBlogForm" (ngSubmit)="onSubmit(newBlogForm.value)">
<div>
<label for="Name">
Blog Name
</label>
<input type="text" formControlName="Name">
</div>
<div>
<label for="TileImage">
Tile Image
</label>
<input type="file" formControlName="TileImage" (change)="onSelectFile($event)" >
</div>
<button type="submit">Create Blog</button>
</form>
.component.ts
selectedFile: File = null;
private newBlogForm: FormGroup;
constructor(private http: HttpClient) { }
ngOnInit() {
this.newBlogForm = new FormGroup({
Name: new FormControl(null),
TileImage: new FormControl(null)
});
}
onSelectFile(fileInput: any) {
this.selectedFile = <File>fileInput.target.files[0];
}
onSubmit(data) {
const formData = new FormData();
formData.append('Name', data.Name);
formData.append('TileImage', this.selectedFile);
this.http.post('your_url_here', formData)
.subscribe(res => {
alert('Uploaded!!');
});
this.newBlogForm.reset();
}
测试结果
这篇关于如何将文件从Angular上传到ASP.NET Core Web API的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!