Question

我有一个迷茫的问题。我有一些材料扩展面板，通过遍历包含我拥有的数据的变量来填充标题，该变量是对象数组-在该对象数组中，有一个键，其值为扩展面板标题。还有一个键，值是另一个对象数组，我要遍历该对象以在每个扩展面板内部填充材质表。

这是我到目前为止所拥有的...

titleGroups.ts：

export const titles = [
    {
        title: 'First Title',
        titleId: 'firstTitle',
        info: [
            { name: 'Info One', code: 'infoOne' },
            { name: 'Info Two', code: 'infoTwo' },
            { name: 'Info Three', code: 'infoThree' },
            { name: 'Info Four', code: 'infoFour' }
        ]
    },
    {
        title: 'Second Title',
        titleId: 'secondTitle',
        info: [
            { name: 'Package', code: 'package' },
            { name: 'Package Two', code: 'packageTwo' } 
        ]
    },
    {
        title: 'Third Title',
        titleId: 'thirdTitle',
        info: [
            { name: 'Widget One', code: 'widgetOne' },
            { name: 'Widget Two', code: 'widgetTwo' },
            { name: 'Widget Three', code: 'widgetThree' },
            { name: 'Widget Four', code: 'widgetFour' }
        ]
    }
]

title.component.ts：

import {Component} from '@angular/core';
import {SelectionModel} from '@angular/cdk/collections';
import {MatTableDataSource} from '@angular/material';
import {titles} from './titleGroups';

export interface TitleNames {
    name: string;
}

const TITLES: any[] = titles;

let TITLE_NAMES;
for(let i = 0; i < TITLES.length; i++)
    for(let j = 0; j < TITLES[i].info.length; j++)
        TITLE_NAMES = TITLES[i].info;

@Component({
    selector: 'aa-titles',
    templateUrl: './aa-titles.component.html',
    styleUrls: ['./aa-titles.component.scss']
})

export class TitlesComponent {
    displayedColumns: string[] = ['select', 'name'];
    dataSource = new MatTableDataSource<TitleNames>(TITLE_NAMES);
    selection = new SelectionModel<TitleNames>(true, []);
    titleData: any;

    constructor() {
        this.titleData = TITLES;
    }

    isAllSelected() {
        const numSelected = this.selection.selected.length;
        const numRows = this.dataSource.data.length;

        return numSelected === numRows;
    }

    masterToggle() {
        this.isAllSelected() ?
            this.selection.clear() :
            this.dataSource.data.forEach(row => this.selection.select(row));
    }
}

title.component.html：

<mat-accordion multi="true">
    <mat-expansion-panel *ngFor="let item of titleData">
        <mat-expansion-panel-header>{{item.title}}</mat-expansion-panel-header>

        <table mat-table [dataSource]="dataSource" class="mat-elevation-z8">
            <!-- Checkbox Column -->
            <ng-container matColumnDef="select">
                <th mat-header-cell *matHeaderCellDef>
                    <mat-checkbox (change)="$event ? masterToggle() : null"
                                  [checked]="selection.hasValue() && isAllSelected()"
                                  [indeterminate]="selection.hasValue() && !isAllSelected()">
                    </mat-checkbox>
                </th>
                <td mat-cell *matCellDef="let row">
                    <mat-checkbox (click)="$event.stopPropagation()"
                                  (change)="$event ? selection.toggle(row) : null"
                                  [checked]="selection.isSelected(row)">
                    </mat-checkbox>
                </td>
            </ng-container>

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

            <tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
            <tr mat-row *matRowDef="let row; columns: displayedColumns;"
                (click)="selection.toggle(row)">
            </tr>
        </table>
    </mat-expansion-panel>
</mat-accordion>

正在发生的是，在每个扩展面板下，它仅显示每个扩展面板下 titleGroups.ts 中标题的最后一个元素的数据。

我想要的是让相应的扩展面板显示正确的数据

第一个标题扩展面板显示一个显示以下内容的表格：

Info One

Info Two

Info Three

Info Four

第二个标题扩展面板以显示一个表格，显示：

Package

Package Two

以此类推。我不知道该怎么做-非常感谢您的帮助！

Answer 1

您应该为每个表定义单独的dataSource-s和selectionModel-s：例如，您可以在constructor中定义这样的数组：

this.titlesForIterate = titles.map(item => { 
    // I'm not doing it here, but you can also deep clone the item object first 
    item.dataSource = new MatTableDataSource<WidgetNames>(item.info);
    item.selectionModel = new SelectionModel<TitleNames>(true, []);
    return item;
};

然后在expandPanels的titlesForIterate中使用*ngFor。

<mat-expansion-panel *ngFor="let item of titlesForIterate">

然后在每个扩展面板内部使用自己的dataSource和selectionModel成员作为其表。

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

    ...
                <mat-checkbox (change)="$event ? masterToggle() : null"
                              [checked]="item.selection.hasValue() && isAllSelected(item)"
                              [indeterminate]="item.selection.hasValue() && !isAllSelected(item)">
                </mat-checkbox>
    ...

注释：不要忘记重构isAllSelected方法以接收父对象作为参数。

Angular 6-遍历材料扩展面板中的材料表

1 个答案: