控制MatTable列的宽度

.custom-width {
  width: 200px;
}

<ng-container matColumnDef="column1">
  <th mat-header-cell *matHeaderCellDef> Column 1 </th>
  <td mat-cell *matCellDef="let element" [style.flex]="1"> {{element.column1}} </td>
</ng-container>

<ng-container matColumnDef="column2">
  <th mat-header-cell *matHeaderCellDef> Column 2 </th>
  <td mat-cell *matCellDef="let element" [style.flex]="2"> {{element.column2}} </td>
</ng-container>

<ng-container matColumnDef="column3">
  <th mat-header-cell *matHeaderCellDef> Column 3 </th>
  <td mat-cell *matCellDef="let element" [style.flex]="1"> {{element.column3}} </td>
</ng-container>

<ng-container matColumnDef="column1">
  <th mat-header-cell *matHeaderCellDef> Column 1 </th>
  <td mat-cell *matCellDef="let element">
    <div style="width: 200px;"> {{element.column1}} </div>
  </td>
</ng-container>