Javascript 无法读取属性'；价值'；在Object.onClick处为null的角度

我想在视图中查看上传的文件按钮，但单击视图按钮时，错误显示为

无法读取null的属性“value” at Object.onClick

.component.ts

export class OnboardingProcessComponent implements OnInit {
//some code..
  measureDetailsForm = new FormGroup({});
  measureDetailsModel: any = {};
  measureDetailsOptions: FormlyFormOptions = {};
  {
          className:'flex-1',
          type: 'onboarding-file',
          key: 'PAS_20350_Certificate',
          templateOptions: {
            label: 'PAS 2030',
            change: (field, $event)=> {
              console.log($event);
              console.log(field);
            }
          },
          },
        {
           type: 'button',
           templateOptions: {
             //label: 'PAS 2030',
             text: 'VIEW',
             onClick: ($event) => {
              //  this.form.get('someInput').setValue('clicked!');
               this.openFile(this.measureDetailsForm.get('PAS_20350_Certificate').value)
             },
           },
},
 ngOnInit(): void {

}

openFile(fileUrl){
    window.open(fileUrl, '_blank')
  }

import { Component } from '@angular/core';
import { FieldType } from '@ngx-formly/core';

@Component({
  selector: 'formly-field-button',
  template: `
    <div>
      <button [type]="to.type" class="lg-blue-button" (click)="onClick($event)">
        {{ to.text }}
      </button>
    </div>
  `,
})
export class FormlyFieldButton extends FieldType {
  onClick($event) {
    if (this.to.onClick) {
      this.to.onClick($event);
    }
  }
}

我使用了formly，因此我单独创建了按钮组件，用于创建按钮，如

按钮类型.组件.ts

export class OnboardingProcessComponent implements OnInit {
//some code..
  measureDetailsForm = new FormGroup({});
  measureDetailsModel: any = {};
  measureDetailsOptions: FormlyFormOptions = {};
  {
          className:'flex-1',
          type: 'onboarding-file',
          key: 'PAS_20350_Certificate',
          templateOptions: {
            label: 'PAS 2030',
            change: (field, $event)=> {
              console.log($event);
              console.log(field);
            }
          },
          },
        {
           type: 'button',
           templateOptions: {
             //label: 'PAS 2030',
             text: 'VIEW',
             onClick: ($event) => {
              //  this.form.get('someInput').setValue('clicked!');
               this.openFile(this.measureDetailsForm.get('PAS_20350_Certificate').value)
             },
           },
},
 ngOnInit(): void {

}

openFile(fileUrl){
    window.open(fileUrl, '_blank')
  }

import { Component } from '@angular/core';
import { FieldType } from '@ngx-formly/core';

@Component({
  selector: 'formly-field-button',
  template: `
    <div>
      <button [type]="to.type" class="lg-blue-button" (click)="onClick($event)">
        {{ to.text }}
      </button>
    </div>
  `,
})
export class FormlyFieldButton extends FieldType {
  onClick($event) {
    if (this.to.onClick) {
      this.to.onClick($event);
    }
  }
}

从'@angular/core'导入{Component}；
从'@ngx formly/core'导入{FieldType}；
@组成部分({
选择器：“表单字段按钮”，
模板：`
{{to.text}}
`,
})
导出类FormlyFieldButton扩展FieldType{
onClick（$event）{
if（this.to.onClick）{
this.to.onClick（$event）；
}
}
}

Hello StackOverFlow。代码中存在多个语法错误，是否尝试编辑代码？