我正在将应用程序写入Angular并且必须上传文件 . 网络显示状态：200但没有响应，我的后端没有收到任何文件 .

问题是.. 1.为什么请求方法是选项？（CORS可能与此有关！但我已经在另一台机器上进行了测试，其中CORS不是问题，因为它在同一端口上）

2.使用文件上传代码时如何将Content-Type从text / plain更改为multipart / form-data？

这是使用文件上传器时浏览器的网络报告：

Request URL:http://localhost:5000/clari5-cc/rest/1.0/installation/upload
Request Method:OPTIONS
Status Code:200 OK
Remote Address:[::1]:5000
Response Headers
view source
Allow:POST, OPTIONS
Content-Type:text/plain
Request Headers
view source
Accept:*/*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:en-US,en;q=0.8
Access-Control-Request-Headers:
Access-Control-Request-Method:POST
Connection:keep-alive
Host:localhost:5000
Origin:http://evil.com/
Referer:http://localhost:3000/

但我的旧运行应用程序过去常常在网络响应中获取此数据：我可以看到一个显着的差异 .

Request URL:http://localhost:5000/try/rest/1.0/installation/upload
Request Method:POST
Status Code:200 OK
Remote Address:[::1]:5000
Response Headers
view source
Content-Type:application/json
Transfer-Encoding:chunked
Request Headers
view source
Accept:application/json, text/javascript, */*; q=0.01
Accept-Encoding:gzip, deflate
Content-Type:multipart/form-data; boundary=----        WebKitFormBoundaryB06sfkK4FgTODz0F
Cookie:Webstorm-e27c5fb2=42da3160-45c3-490c-a5d9-b0ed07b63022
Host:localhost:5000
Origin:http://evil.com/
Referer:http://localhost:5000/try/mainPage.html
Request Payload
------WebKitFormBoundaryB06sfkK4FgTODz0F
Content-Disposition: form-data; name="uploadedFiles";             filename="installer.tar"
Content-Type: application/x-tar

这里是代码，我没有任何线索如何进行更改，没有提供选项也没有例子？任何帮助和建议将不胜感激，谢谢

export class AppComponent {
  public uploader:FileUploader = new FileUploader({url: "http://localhost:5000/try/rest/1.0/installation/upload"});
  public hasBaseDropZoneOver:boolean = false;
  public hasAnotherDropZoneOver:boolean = false;

  public fileOverBase(e:any):void {
    this.hasBaseDropZoneOver = e;
  }

  public fileOverAnother(e:any):void {
    this.hasAnotherDropZoneOver = e;
 }
}

或者在

export class AppDemoComponent implements OnInit {
 private zone: NgZone;
 private basicOptions: Object;
 private progress: number = 0;
 private response: any = {};

 ngOnInit() {
   this.zone = new NgZone({ enableLongStackTrace: false });
   this.basicOptions = {
     url: 'http://api.ng2-uploader.com:10050/upload'
   };
 }

 handleUpload(data: any): void {
   this.zone.run(() => {
     this.response = data;
     this.progress = data.progress.percent / 100;
   });
 }
}
angular