JSON中位于位置0的JSON中的意外令牌P.Angular中的错误 - 码农俱乐部 - Golang中国

当我从Angular表单发布数据时，我期望从后端输出。问题是我可以在控制台中看到输出，但出在错误中。

error: SyntaxError: Unexpected token P in JSON at position 0 at JSON.parse (<anonymous>) at XMLHttpRequest.onLoad
text: "Success"
__proto__: Object
headers: HttpHeaders {normalizedNames: Map(0), lazyUpdate: null, lazyInit: ƒ}
message: "Http failure during parsing for http://localhost:5000/api"
name: "HttpErrorResponse"
ok: false
status: 200
statusText: "OK"
url: "http://localhost:5000/api"

我只是将数据记录到控制台。

form: FormGroup;

constructor(
  public fb: FormBuilder,
  private http: HttpClient
) {
  this.form = this.fb.group({
    inputText: ['']
  })
}
submitForm() {
  var formData: any = new FormData();
  this.http.post('http://localhost:5000/api', formData).subscribe(
    (res) => console.log(res),
    (err) => console.log(err)

  )
}

<div class="continaer">
  <form [formGroup]="form" (ngSubmit)="submitForm()">
    <div class="form-group">
      <h2 class="card-title">Enter Your text</h2>
      <textarea class="form-control" formControlName="inputText"></textarea>
    </div>
    <div class="form-group">
      <button class="btn btn-danger">Submit</button>
    </div>
  </form>
</div>

我需要在SubmitForm（）中添加的内容