Question

我遇到了一些问题。我在Angular 6中有一个组件，其中正在使用数据生成多个Mat-Table。我在div标签中使用ng-for循环遍历所有Mat-Table数据源。后来我试图在表中添加新行。到这里为止还可以，但是无法获取单击了“添加行”功能的表的实例。在.ts fenter代码中，借助View-Child的方法始终仅获取第一个表的实例。我想获取所有表的实例，通过该实例，我将调用render rows函数来刷新视图中选择的MatTable

为View和TS文件粘贴了示例代码。注意“添加”现在不起作用。

   <div *ngFor="let data of ViewContent">
<button (click)="addElement(event,data?.tableValues,displayedColumns)">Add element</button> <br />
<table   #testTable mat-table [dataSource]="data?.tableValues">

  <!-- Col1 Column -->
  <ng-container matColumnDef="Col1">
    <th mat-header-cell *matHeaderCellDef> Col1 </th>
    <td mat-cell *matCellDef="let element"> {{element.Col1}} </td>
  </ng-container>

  <!-- Col2 Column -->
  <ng-container matColumnDef="Col2">
    <th mat-header-cell *matHeaderCellDef> Col2 </th>
    <td mat-cell *matCellDef="let element"> {{element.Col2}} </td>
  </ng-container>

  <!-- Col3 Column -->
  <ng-container matColumnDef="Col3">
    <th mat-header-cell *matHeaderCellDef> Col3 </th>
    <td mat-cell *matCellDef="let element"> {{element.Col3}} </td>
  </ng-container>

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



<!-- Copyright 2019 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 -->

</div>



import {DataSource} from '@angular/cdk/collections';
import {Component,OnInit,ViewChild} from '@angular/core';
import {BehaviorSubject, Observable} from 'rxjs';
import  DalContentdata from 'Content.json';
import { MatTable } from '@angular/material';

@Component({
  selector: 'cdk-table-basic-example',
  styleUrls: ['cdk-table-basic-example.css'],
  templateUrl: 'cdk-table-basic-example.html',
})
export class CdkTableBasicExample implements OnInit  {
   ViewContent: Object;
   displayedColumns: string[] = ['Col1','Col2','Col3'];

  @ViewChild('testTable') table: MatTable<any>;

  ngOnInit() {
    this.ViewContent =  [
    {
      "title":"abc",
      "tableValues": [
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        }
      ]
    },
    {
       "title":"abc",
      "displayColumns": "Col1,Col2,Col3",
      "tableValues": [
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        }
      ]
    },
    {
       "title":"abc",
      "displayColumns": "Col1,Col2,Col3",
      "tableValues": [
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        },
        {
          "Col1": "Apple",
          "Col2": "Mango",
          "Col3": "Orange"
        }
      ]
    }
  ];
  }


  addElement(event, title, tableDataSource, displayColumns) {
        console.log('beforeAdd', tableDataSource);
    tableDataSource.push({
      Col1: 'Test',Col2:'Test',Col3:'Test'
    })
     console.log('afteradd', tableDataSource);
     this.table.renderRows();

    console.log('afteradd', tableDataSource);
  }


}


/**  Copyright 2019 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 */

Answer 1

您应该使用ViewChild。

html：假设您的表在for循环内运行，并且索引变量名为i：

  <table id="testTable{{i}}" [dataSource]="yourDataSource"><!--data source can be set from ts as well-->

ts：

@ViewChild('testTable1') matTable1: MatTable<any>;
  @ViewChild('testTable2') matTable2: MatTable<any>;
  @ViewChild('testTable3') matTable3: MatTable<any>;

或者当然也可以只使用数组。

别忘了导入它，您将更喜欢使用AfterViewInit生命周期挂钩

  ngAfterViewInit() {
//    this.matTable...
  }

编辑：

如果您希望刷新数据源

this.matTable.dataSource = [... this.data]

您只需传递新数组（带有新引用），它将触发数据更改，并且您的数据表将刷新

如果您希望使用for为每个表创建一个unic ID，

Answer 2

我遇到了类似的问题，并使用ViewChildren而不是ViewChild解决了该问题。

我最初有：

@ViewChild(MatTable) table: MatTable<string>;

然后要调用renderRows，我在打电话

this.table.renderRows();

但是，然后我需要在同一组件中创建另一个表，因此我的代码更改为：

@ViewChildren(MatTable) table !: QueryList<MatTable<string>>;

和

this.table.first.renderRows();
this.table.last.renderRows();

第一个和最后一个是queryList的属性。 https://angular.io/api/core/QueryList#properties

确保要导入MatTable

import { MatTable } from "@angular/material/table";

Answer 3

在html中：

<table
mat-table
id="table"
class="full-width"
[dataSource]="dataSource"
matSort
data-cy="pg_table"
(matSortChange)="onSortData($event)"
#table1
>

在模板中：

@ViewChild('table1', { static: true }) table1: MatTable<any>;

Answer 4

扩展Chishty的答案，如果表为'n'，则可以在循环中使用@ViewChildren并在每个表上调用renderRows()。总体步骤如下-

导入mat-table

从'@ angular / material / table'导入{MatTable};
用@ViewChildren声明QueryList

@ViewChildren（MatTable）csvTable！：QueryList ;
在添加或删除操作上调用renderRows

this.csvTable.toArray（）。forEach（data => data.renderRows（））;
请记住在模板中使用与table-id相同的变量

有关@ViewChildren-Angular Docs的更多信息
有关QueryList-Angular Docs

的更多信息

如果组件中有多个表，则如何获取Mat-Table的实例

4 个答案: