FileUpload in Angular 2

<input type="file" accept=".Jpg,.Jpeg" id="uploadCaptureInputFile" class="form-control" name="documents" (change)="onChange($event)" [(ngModel)]="_FileType"

            #documents="ngModel">

****************Change Event *************

onChange(event: EventTarget) {

    let formData = new FormData();

    let eventObj: MSInputMethodContext = <MSInputMethodContext>event;

    let target: HTMLInputElement = <HTMLInputElement>eventObj.target;

    let files: FileList = target.files;

    this.file = files[0];

    let formData = new FormData();

    formData.append('FileDocument', this.file);

 return this.http.post(`UrlPath`, formData)

      .map((res: Response) => {        

      });

  }

******************WEB API******************

[HttpPost]

public void GetImage()

{

 var ImageData= System.Web.HttpContext.Current.Request.Files["FileDocument"];

 ImageData.SaveAs(Path);

}