Angular 使用.NET Core进行角度多部分上载，文件在后端变为空

我正试图将一个简单的文件上载到我的后端dotnet核心应用程序，但该文件显示为

null

，但

description

不为null

.NET核心控制器：

[AllowAnonymous]
[HttpPost]
[Route("upload")]
public async Task<IActionResult> ImageUpload(IFormFile file, [FromQuery] string description)
{
    if (file == null)
    {
        return BadRequest("Failed to upload file");
    }

    // File is alway null!

    return Ok("Good!");
}

---

您需要将数据作为FormData（）从角度发布，您还可以使用.append（）将描述设置为服务方法中的fd对象。您将使用Request=>Request.Form在API中获取所有附加数据

API

 [HttpPost("SaveProfilePic")]
public ResponseResult SaveProfilePic(IFormFile files)
{
 var file = Request.Form.Files[0];
 var form = Request.Form;
}

棱角分明

<form (ngSubmit)="Save(f)" #f="ngForm">
<input type="file" name="profile_pic" (change)="setProfilePic($event)">
<input type="submit" value="submit" />
</form>
Save(form)
{
 this.MyService.SaveProfilePic(this.profile_pic, 'description').subscribe(res => {

 })
}
    setProfilePic(event:any)
    {
     if (event.target.files && event.target.files[0]) {
     this.profile_pic = event.target.files[0];
     var reader = new FileReader();
     reader.readAsDataURL(event.target.files[0]); // read file as data url
     reader.onload = (event:any) => { // called once readAsDataURL is completed
     }

     }
    }

<form (ngSubmit)="Save(f)" #f="ngForm">
<input type="file" name="profile_pic" (change)="setProfilePic($event)">
<input type="submit" value="submit" />
</form>
Save(form)
{
 this.MyService.SaveProfilePic(this.profile_pic, 'description').subscribe(res => {

 })
}
    setProfilePic(event:any)
    {
     if (event.target.files && event.target.files[0]) {
     this.profile_pic = event.target.files[0];
     var reader = new FileReader();
     reader.readAsDataURL(event.target.files[0]); // read file as data url
     reader.onload = (event:any) => { // called once readAsDataURL is completed
     }

     }
    }

public SaveProfilePic(picture: File,fileName): any {
 const fd = new FormData();
 fd.append('image', picture, fileName);
 return this._http.post(this.url + 'MyController/SaveProfilePic', fd);
}