此问题的解决方法是在Formly的模板选项中使用ng-file-upload插件，并在fileUpload中使用onSuccess和onError来设置上传文件的路径。下面是代码示例：

在Angular应用程序中安装ng-file-upload插件：

npm install ng-file-upload --save

在模块中导入ng-file-upload：

import { ngFileUploadModule } from 'ng-file-upload';

在Formly的模板选项中使用ng-file-upload插件：

import { Component } from '@angular/core';
import { FileUploader } from 'ng-file-upload';

@Component({
  selector: 'my-app',
  template: `
  
  `,
})
export class AppComponent {
  public uploader: FileUploader = new FileUploader({ url: 'uploadUrl' });

  public fields = [
    {
      key: 'document',
      type: 'file',
      templateOptions: {
        label: 'Select a file',
        required: true,
        type: 'file',
      },
      parser: (val) => this.uploader.queue[0]._file.name,
      validators: {
        fileCheck: {
          expression: (control) => {
            return !!control.value;
          },
          message: '$viewValue + " is not a valid file"',
        },
      },
    },
  ];

  public model = {};

  public form = new FormGroup({});
}

在fileUpload中使用onSuccess和onError来设置上传文件的路径：

import { ngFileUploadModule } from 'ng-file-upload';

@Component({
    selector: 'file-upload',
    template: `
        
        Upload
    `,
    providers: [ ng2UploaderService ]
})

export class FileUpload{
    public uploader:FileUploader = new FileUploader({url:'http://localhost:10050/upload'});
    public async uploadedPath: string;

    constructor(protected ng2Uploader: ng2UploaderService) {
      this.up