1. 确保 FormData 对象包含所需的键值对

2. 设置 Content-Type 标头为 'multipart/form-data'

3. 在 .Net Core webAPI 中使用 FromForm 属性将 FormData 数据绑定到模型。

示例代码：

Angular 控制器代码

submitForm() {
  const formData = new FormData();
  formData.append('name', this.name);
  formData.append('email', this.email);
  formData.append('avatar', this.avatarFile, this.avatarFile.name);

  this.http.post('/api/users', formData).subscribe(res => {
    console.log(res);
  });
}

.Net Core webAPI 控制器代码

[HttpPost]
public async Task AddUser([FromForm] UserDto userDto) {
  // userDto now contains the FormData submitted from the Angular app
  // handle saved to DB, etc.

  return Ok();
}