在Angular表单数组中进行文件上传可以遵循以下步骤：

1. 首先，在模板中创建一个表单数组，其中包含file类型的input元素和对应的Form Control名称。例如：

2. 在组件中，定义表单数组和对应的Form Builder。例如：

import { FormBuilder, FormGroup, FormArray } from '@angular/forms';

@Component({
  selector: 'app-file-upload',
  templateUrl: './file-upload.component.html',
  styleUrls: ['./file-upload.component.css']
})
export class FileUploadComponent {
  myFormGroup: FormGroup;
  filesArray: FormArray;

  constructor(private formBuilder: FormBuilder) { }

  ngOnInit() {
    this.myFormGroup = this.formBuilder.group({
      filesArray: this.formBuilder.array([this.createFileControl()])
    });
    this.filesArray = this.myFormGroup.get('filesArray') as FormArray;
  }

  createFileControl(): FormGroup {
    return this.formBuilder.group({
      'file-control': ['']
    });
  }
}

3. 创建一个方法，以在每个输入元素中选择文件时调用。在该方法中，将文件添加到FormData中并将其发送到服务器。例如：

onFileChange(event, index) {
    let fileList: FileList = event.target.files;
    if (fileList.length > 0) {
      let file: File = fileList[0];
      let formData: FormData = new FormData();
      formData.append('file', file, file.name);
      let headers = new HttpHeaders();
      // Set headers etc. as needed

      // Send file to server using http.post or whatever method you prefer
      // For example:
      this.http.post('/api/upload', formData, { headers: headers }).subscribe(
        response => {
          // Handle server response as needed
        },