Angular Material v6 Mat-Footer - "无法读取未定义的属性'模板'"

Question

为了这个目的,我最近在升级到角度6之后尝试在mat-table组件中实现一个页脚行,但是在表格中添加mat-footer-cell和mat-footer-row元素后,我得到以下内容错误:

错误类型错误:无法在MatFooterRowDef.push读取未定义的属性"模板"../ node_modules/@angular/cdk/esm5/table.es5.js.CdkFooterRowDef.extractCellTemplate(vendor.js:17400)

该表仍显示在页面上,但没有数据,没有页脚行,并且每个列标题右侧的T符号.

HTML:

  <ng-container matColumnDef="total">

    <mat-header-cell *matHeaderCellDef mat-sort-header style="width: 15%; flex: none">Total</mat-header-cell>

    <mat-cell *matCellDef="let item" style="width: 15%; flex: none">{{item.total | currency: 'GBP'}}</mat-cell>

    <td mat-footer-cell *matFooterCellDef>100</td>

  </ng-container>

  <mat-header-row *matHeaderRowDef="tableColumns"></mat-header-row>

  <mat-row *matRowDef="let row; columns: tableColumns" (click)="editItem(row)"></mat-row>

  <tr mat-footer-row *matFooterRowDef="tableColumns"></tr>

</mat-table>

Answer 1

修复:在材料文档中没有明确说明,但所有列都必须包含一个<mat-footer-cell/>元素,即使只有一列包含内容.

Answer 2

您可以定义自己的“tableFooterColumns”变量。

tableFooterColumns: string[] = ['total'];

并在模板中使用它（根据需要更改“colspan”）：

 <tr mat-footer-row *matFooterRowDef="tableFooterColumns" colspan="2"></tr>

Answer 3

需要为每列包含mat-footer-cell：

<div class="example-container mat-elevation-z8">
  <mat-table #table [dataSource]="dataSource">

    <mat-header-row *matHeaderRowDef="displayedColumns; sticky: true"></mat-header-row>
    <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>

    <ng-container matColumnDef="categoryName">
      <mat-header-cell *matHeaderCellDef> First Name </mat-header-cell>
      <mat-cell *matCellDef="let row"> {{row.firstName}} </mat-cell>
      
      //This is the part for which the code is breaking
      <mat-footer-cell *matFooterCellDef> Your footer column Name will goes here </mat-footer-cell>**
    </ng-container>
    <ng-container matColumnDef="categoryName">
      <mat-header-cell *matHeaderCellDef> Last Name </mat-header-cell>
      <mat-cell *matCellDef="let row"> {{row.lastName}} </mat-cell>
      
      //This need to be included in all your columns
      <mat-footer-cell *matFooterCellDef> Your 2nd footer column Name will goes here </mat-footer-cell>**
    </ng-container>
    <mat-footer-row *matFooterRowDef="displayedColumns; sticky: true"></mat-footer-row>
  </mat-table>
</div>