C# 角度服务调用的值为Null

我在控制器上的文件名值为null。我从我的组件中得到了这个代码。使用Angular 7和.net core 2.1

handleFileInput(event) {

const file = event.target.files[0];
this.fileName = file.name;

console.log('This file - ' + this.fileName);

this.route.params.subscribe(params => {
  this.fileService.getHeaders().subscribe((data: IApiHelper) => {
    this.fileService.createHeader(data);
    this.fileService.saveFileProperties(this.fileName).subscribe(s => {
      console.log('this is inside subscribe - ' + s);
      this.fileName = s;        
    },
      (error) => { console.log(error); }
    );
  });
})

}

这是服务代码：

saveFileProperties(fileName: string ) {return this.http.post<string>('/api/aspera/SaveFileToDatabase',fileName, this.httpOptions);

---

您需要指定POST应使用FromBody属性从邮件正文中检索文件名：

public IActionResult SaveFileToDatabase([FromBody]string fileName){

---

您应该传递一个具有

fileName

属性的对象

this.fileService.saveFileProperties({fileName: this.fileName}).subscribe( //..

this.fileService.saveFileProperties({fileName: this.fileName}).subscribe( //..