angular - Angular 中的 Angular Material mat-select 动态数据绑定

Question

我正在使用 Angular 6 和 Angular 材质。当我单击编辑按钮时，将在选择时初始化辅助值、SSC 和男性值。但我做不到。单击编辑按钮后，我只能在下拉列表中显示男性值。所以我想在下拉列表中显示所有值并传递对象以进行动态选择。谢谢。

我的代码链接在这里：stackblitz 链接

Answer 1

您可以尝试使用此解决方案

我在Stackblitz上创建了一个演示

组件.ts

  editInfo(educationInfo) {
    this.education_level = educationInfo.aa;
    this.exam_title = educationInfo.bb;
    this.gender = educationInfo.cc;
    this.educationLevelChangeAction(this.education_level);
  }

  educationLevelChangeAction(education) {
    this.exam_title = "";
    let dropDownData = this.educationList.find((data: any) => data.educationLevelName === education);
    if (dropDownData) {
      this.degreeTitleList = dropDownData.degreeTitleList;
    } else {
      this.degreeTitleList = [];
    }

  }

组件.html

<mat-form-field>
  <mat-select placeholder="Select Level of Education" name="education_level" (selectionChange)="educationLevelChangeAction(education_level)" [(ngModel)]="education_level" >
    <mat-option *ngFor="let education of educationList" [value]="education.educationLevelName" >{{ education.educationLevelName }}</mat-option>
  </mat-select>
</mat-form-field>

<mat-form-field>
  <mat-select placeholder="Select Exam/Degree Title" name="exam_title" [(ngModel)]="exam_title">
    <mat-option *ngFor="let degreeTitle of degreeTitleList" [value]="degreeTitle">{{ degreeTitle }}</mat-option>
  </mat-select>
</mat-form-field>

<mat-form-field>
  <mat-select [(ngModel)]="gender">
    <mat-option *ngFor="let gender of genderList" [value]="gender">{{ gender }}</mat-option>
  </mat-select>
</mat-form-field>



<p>You selected: {{education_level}}  {{exam_title}} {{gender}}</p>

Answer 2

在您的代码中，您将对象绑定到 [value]，因此它无法正确绑定它，如果您像在性别部分中所做的那样将值更改为字符串就可以了，例如：

[value]从educationthat is object 更改为that education.educationLevelNameis a string 现在它可以正常工作了。

<mat-form-field>
  <mat-select placeholder="Select Level of Education" name="education_level" (selectionChange)="educationLevelChangeAction(education_level)" [(ngModel)]="education_level" >
    <mat-option *ngFor="let education of educationList" [value]="education.educationLevelName" >{{ education.educationLevelName }}</mat-option>
  </mat-select>
</mat-form-field>