Angular Material 垫表行分组

Question

撇开为其特定表提供行分组的库不谈，我正在尝试在 Angular Material 2 mat-table 上实现这样的功能。它没有这样的功能。

填充表格的项目:

export class BasketItem{
    public id: number;
    public position: number;
    public quantity: number;
    public groupId: number;
} 

Grouping rows that have same groupId property in the following table

 <mat-table class="mat-elevation-z8" [dataSource]="dataSource" multiTemplateDataRows matSort matSortActive="position" matSortDirection="asc" matSortDisableClear >

      <!-- Position Column -->  
      <ng-container matColumnDef="position">
        <mat-header-cell *matHeaderCellDef mat-sort-header>
          <b>Position</b>
        </mat-header-cell>
        <mat-cell *matCellDef="let basketItem">{{basketItem.position}}</mat-cell>
      </ng-container>

      <!-- Quantity Column -->
      <ng-container matColumnDef="quantity">
        <mat-header-cell *matHeaderCellDef>
          <b>Quantity</b>
        </mat-header-cell>
         <mat-cell *matCellDef="let basketItem">{{basketItem.quantity}}</mat-cell>
      </ng-container>

      <!-- GroupId Column -->  
      <ng-container matColumnDef="position">
        <mat-header-cell *matHeaderCellDef mat-sort-header>
          <b>GroupId </b>
        </mat-header-cell>
        <mat-cell *matCellDef="let basketItem">{{basketItem.GroupId }}</mat-cell>
      </ng-container>


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

      <mat-row *matRowDef="let basketItem; columns: displayedColumns;" (click)="onSelect(basketItem)"></mat-row>

    </mat-table>

关于如何处理行分组有什么想法吗？

Answer 1

一个非常简单的答案是按 GroupID 排序，这会将这些行分组。不过，我猜您希望在每个组之前显示一个标题行。

您可以提供替代方案 <mat-row *matRowDef="...使用 where 子句。这可用于显示一组非默认的列。如果应该使用 matRowDef，where 子句采用返回 true 的函数。

然后，您提供给表格的数据将是散布在组行中的数据行，并且该函数会区分彼此。以Basic use of <table mat-table> 作为初学者，手动添加组并将 where 子句函数添加到 app/table-basic-example.ts:

    import {Component} from '@angular/core';

    export interface PeriodicElement {
      name: string;
      position: number;
      weight: number;
      symbol: string;
    }

    export interface Group {
      group: string;
    }

    const ELEMENT_DATA: (PeriodicElement | Group)[] = [
      {group: "Group 1"},
      {position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H'},
      {position: 2, name: 'Helium', weight: 4.0026, symbol: 'He'},
      {position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li'},
      {position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be'},
      {group: "Group 2"},
      {position: 5, name: 'Boron', weight: 10.811, symbol: 'B'},
      {position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C'},
      {position: 7, name: 'Nitrogen', weight: 14.0067, symbol: 'N'},
      {group: "Group 3"},
      {position: 8, name: 'Oxygen', weight: 15.9994, symbol: 'O'},
      {position: 9, name: 'Fluorine', weight: 18.9984, symbol: 'F'},
      {position: 10, name: 'Neon', weight: 20.1797, symbol: 'Ne'},
    ];

    /**
     * @title Basic use of `<table mat-table>`
     */
    @Component({
      selector: 'table-basic-example',
      styleUrls: ['table-basic-example.css'],
      templateUrl: 'table-basic-example.html',
    })
    export class TableBasicExample {
      displayedColumns: string[] = ['position', 'name', 'weight', 'symbol'];
      dataSource = ELEMENT_DATA;

      isGroup(index, item): boolean{
        return item.group;
      }
    }


    /**  Copyright 2018 Google Inc. All Rights Reserved.
        Use of this source code is governed by an MIT-style license that
        can be found in the LICENSE file at http://angular.io/license */

并将 groupHeader 列和额外的 matRowDef 添加到 app/table-basic-example.html:

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

      <!--- Note that these columns can be defined in any order.
            The actual rendered columns are set as a property on the row definition" -->

      <!-- Position Column -->
      <ng-container matColumnDef="position">
        <mat-header-cell *matHeaderCellDef> No. </mat-header-cell>
        <mat-cell *matCellDef="let element"> {{element.position}} </mat-cell>
      </ng-container>

      <!-- Name Column -->
      <ng-container matColumnDef="name">
        <mat-header-cell *matHeaderCellDef> Name </mat-header-cell>
        <mat-cell *matCellDef="let element"> {{element.name}} </mat-cell>
      </ng-container>

      <!-- Weight Column -->
      <ng-container matColumnDef="weight">
        <mat-header-cell *matHeaderCellDef> Weight </mat-header-cell>
        <mat-cell *matCellDef="let element"> {{element.weight}} </mat-cell>
      </ng-container>

      <!-- Symbol Column -->
      <ng-container matColumnDef="symbol">
        <mat-header-cell *matHeaderCellDef> Symbol </mat-header-cell>
        <mat-cell *matCellDef="let element"> {{element.symbol}} </mat-cell>
      </ng-container>

      <ng-container matColumnDef="groupHeader">
        <mat-cell *matCellDef="let group">{{group.group}}</mat-cell>
      </ng-container>

      <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
      <mat-row *matRowDef="let row; columns: displayedColumns"></mat-row>
      <mat-row *matRowDef="let row; columns: ['groupHeader']; when: isGroup"> </mat-row>

    </mat-table>



    <!-- Copyright 2018 Google Inc. All Rights Reserved.
        Use of this source code is governed by an MIT-style license that
        can be found in the LICENSE file at http://angular.io/license -->

这是一个完成的stackblitz按元素的首字母分组。

这里是一个更发达的stackblitz只需提供您要分组的列列表，它就会为您插入分组行。您还可以单击组行以展开或折叠它们

最后这是一个 Github project从 Material 代码库修改 MatTableDataSource 类的副本。与过滤器和排序一起工作得很好，但与分页器“竞争”，因为它们都以不同的方式限制记录的 View 。