无法使Angular Material2表格排序和Paginator起作用

Question

我一直在尝试在我的材料表上实现排序和paginator。

以下给我我的表格，但是当我单击标头时，没有任何排序发生，并且尽管Paginator表明当我单击Paginator按钮时，列出了整个数据集，但也只有10个结果。效仿：

import {
  AfterViewInit, Component, Input, OnChanges, OnInit, SimpleChanges,
  ViewChild
} from '@angular/core';
import {MatSort, MatPaginator, MatTableDataSource} from '@angular/material';
import {SelectionModel} from '@angular/cdk/collections';
import {ApiConnectService} from '../../../../../assets/services/api.connect.service';
@Component({
  selector: 'app-review-table',
  templateUrl: './review.table.component.html',
  styleUrls: ['./review.table.component.scss']
})
export class ReviewTable implements OnInit, AfterViewInit, OnChanges {
  @Input() purchaseOrders: Array<object>;
  @Input() searchKey: string;
  @ViewChild(MatSort) sort: MatSort;
  @ViewChild(MatPaginator) paginator: MatPaginator;
  dataSource: MatTableDataSource<any>;
  selection = new SelectionModel<any>(true, null);
  displayedColumns = ['rowcount', 'siteId', 'importDate', 'poPoNumber', 'poPrice'];
  constructor(private _api: ApiConnectService) { }
  ngOnInit() {
    this._api.getPurchaseOrders()
      .subscribe(data => {
        this.dataSource = new MatTableDataSource(data);
      }, err => {
        console.log(err);
      });
  }
  ngOnChanges(changes: SimpleChanges) {
    for (let property in changes) {
      if (changes[property].previousValue !== changes[property].currentValue){
        if (property === 'searchKey') {
          this.applyFilter(this.searchKey);
        }
      }
    }
  }
  ngAfterViewInit() {
    this.dataSource.paginator = this.paginator;
    this.dataSource.sort = this.sort;
  }
  applyFilter(filterValue: string) {
    filterValue = filterValue.trim();
    filterValue = filterValue.toLowerCase();
    this.dataSource.filter = filterValue;
  }
}

在第二个实现中，我仅放置了排序代码，并将数据集的值设置为我可观察的可观察到的值，我在数据集声明的面前第二次添加了@ViewChild(MatSort)。这种怪异的实验是针对指南https://material2-docs-dev.firebaseapp.com/components/components/table/examples规定的规定，导致了按预期工作的分类：

import { AfterViewInit, Component, OnInit, ViewChild } from '@angular/core';
import { ApiConnectService } from '../../../../assets/services/api.connect.service';
import { MatSort, MatTableDataSource } from '@angular/material';
import { SelectionModel } from '@angular/cdk/collections';

@Component({
  selector: 'app-menu3',
  templateUrl: './purchase.orders.component.html',
  styleUrls: ['./purchase.orders.component.scss']
})
export class PurchaseOrders implements OnInit, AfterViewInit {
  @ViewChild(MatSort) sort: MatSort;
  @ViewChild(MatSort) dataSource: MatTableDataSource<any>;
  multipleSelect = true;
  selection = new SelectionModel<any>(this.multipleSelect, null);
  displayedColumns = ['siteId', 'importDate', 'poPoNumber', 'poPrice'];
  constructor(private _api: ApiConnectService) {
  }
  ngOnInit() {
    this._api.getPurchaseOrders()
      .subscribe(data => {
        this.dataSource = new MatTableDataSource(data);
      }, err => {
        console.log(err);
      });
  }
  ngAfterViewInit() {
    this.dataSource.sort = this.sort;
  }
  applyFilter(filterValue: string) {
    filterValue = filterValue.trim();
    filterValue = filterValue.toLowerCase();
    this.dataSource.filter = filterValue;
  }
}

问题在于我会遇到此浏览器 - 综合错误，从而导致我的浏览器动画发送到错误的元素 ->我的数据集。错误谈论了错误类型的数据源(我猜？(，但随后显示了表格：

：

core.js:1448 ERROR Error: Provided data source did not match an array, Observable, or DataSource
    at getTableUnknownDataSourceError (table.es5.js:379)
    at MatTable.CdkTable._observeRenderChanges (table.es5.js:860)
    at MatTable.CdkTable.ngAfterContentChecked (table.es5.js:577)
    at callProviderLifecycles (core.js:12702)
    at callElementProvidersLifecycles (core.js:12673)
    at callLifecycleHooksChildrenFirst (core.js:12656)
    at checkAndUpdateView (core.js:13806)
    at callViewAction (core.js:14153)
    at execComponentViewsAction (core.js:14085)
    at checkAndUpdateView (core.js:13808)

简而言之，这不是解决方案。

我尝试用@ViewChild(MatSort) @ViewChild(MatPaginator) dataSource: MatTableDataSource<any>;将我的小骇客插入一倍，但这毫无结果。它只是忽略了matpaginator部分。Paginator仍然没有链接。

是该表被声明的组成部分是与API调用的数据相同，还是允许您在父级中进行数据调用并通过@Input？

将其传递给表格。

在后一种情况下，我将桌子放在一个小时候到检索数据的组件的后一种情况下，我缺少什么列和分页？

当我强迫工作时，为什么我会遇到此错误？

Answer 1

收到一些异步数据后创建Mattabledatasource。因此，当您这样做

时

 ngAfterViewInit() {
    this.dataSource.paginator = this.paginator;
    this.dataSource.sort = this.sort;
  }

this.dataSource可能为null

您可以更改

吗？

constructor(private _api: ApiConnectService) { }
  ngOnInit() {
    this._api.getPurchaseOrders()
      .subscribe(data => {
        this.dataSource = new MatTableDataSource(data);
      }, err => {
        console.log(err);
      });
  }

to

  constructor(private _api: ApiConnectService) {
      this.dataSource = new MatTableDataSource(data); // create MatTableDataSource (synchronous) here to allow sort / filtering binding
  }
  ngOnInit() {
    this._api.getPurchaseOrders()
      .subscribe(data => {
        this.dataSource.data = data; // populate data here 
      }, err => {
        console.log(err);
      });
  }