完整控制台错误：

ERROR TypeError: Cannot read properties of undefined (reading 'data")

at Oviewer Component 15A11Selected (oviewer.component.ts:97:37)

at OviewerComponent.checkbeaLabel (aviewer.component.ts:114:22)

at Oviewer Component th 26 Template (oviewer.component.html:79:68)

Oviewer.component.html

<div class="stable mat-elevation-z8">

<table mat-table [dataSource]="dataSource" class="mat-elevation-z8">

<!-- Checkbox Column --> 
<ng-container matColumnDef="select">

<th mat-header-cell *matHeaderCellDef>

<mat-checkbox

(change)="$event? toggleAllRows(): null" color="primary"

[checked]="selection.hasValue() && isAllSelected()"

[indeterminate]-"selection.hasValue() && lisAllSelected()"

[aria-label]="checkboxLabel()"

</mat-checkbox>

Oviewer.component.ts

iSAllSelected() {

const numSelected =this.selection.selected.length;

const numRows =this.dataSource.data.length;

return numSelected === numRows;

/** Selects all rows if they are not all selected; otherwise clear selection.*/

toggleAllRows() {

if (this.isAllSelected())

{

this.selection.clear();

return;

}

this.selection.select(...this.dataSource.data);

}

/** The label for the checkbox on the passed row */

checkboxLabel(row?: any): string { if (!row) { return ${this.isAllSelected() ? 'deselect' : 'select') all';

}

我无法找到此问题的解决方案。有人能帮助我吗为什么我得到这个控制台错误？