表单控件更新值在ngoninit()中不更新

我正在创建JSON中的动态表单 ngOnInit()

我要做的是在 恩戈尼尼特() .

ngOnInit(){
  ...Form creation...
  this.parsedJson.sections[0].form.controls['clientName'].setValue("John");
}

它不会以这种方式更新控件,如果我手动触发相同的操作(例如:按钮单击),它将进行更新。
this.parsedJson.sections[0].form.controls['clientName'].setValue("John");

我也试过用 patchValue 而不是 setValue 但结果是一样的。

表单创建:

for(let section of this.parsedJson2.sections){
  section.form  = new FormGroup({});
  if(section.section_type == 'normal') {
    for (let question of section.question_list) {
      if (question.qtype == 'input-text') {
        const control: FormControl = new FormControl(question.answer, Validators.required);
        section.form.addControl(question.key, control);
      }
      if (question.qtype == 'input-email') {
        const control: FormControl = new FormControl(question.answer, Validators.email);
        section.form.addControl(question.key, control);
      }
      if (question.qtype == 'multi-choice') {
        for (let choice of question.qchoices) {
          const control: FormControl = new FormControl(choice.selected, Validators.required);
          section.form.addControl(choice.key, control);
        }
      }
      else {
        const control: FormControl = new FormControl(question.answer, Validators.required);
        section.form.addControl(question.key, control);
      }
    }
  }
}