javascript - 是否可以使用 TypeScript 在 HTML 中“预渲染”一个 div？

Question

我有一个带有大角材料表的容器。我想“预渲染”这个 div，因为当我垂直或水平滚动时整个页面都会出错。

<div class="table-container" id="prerender">
   <table mat-table [dataSource]="dataSource" matSort class="mat-elevation-z8">
   ...
   </table>
</div>

是否有可能的解决方案说应该首先呈现该 div 的浏览器？也许：

document.getElementById("prerender").render()

标签： javascripthtmlangulartypescriptdom

Answer 1

我强烈建议您使用Angular 材质 Paginator。根据 angular material documentations，您的html文件应如下所示：

<mat-form-field>
  <input matInput (keyup)="applyFilter($event.target.value)" placeholder="Filter">
</mat-form-field>

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

    <!-- ID Column -->
    <ng-container matColumnDef="id">
      <th mat-header-cell *matHeaderCellDef mat-sort-header> ID </th>
      <td mat-cell *matCellDef="let row"> {{row.id}} </td>
    </ng-container>

    <!-- Progress Column -->
    <ng-container matColumnDef="progress">
      <th mat-header-cell *matHeaderCellDef mat-sort-header> Progress </th>
      <td mat-cell *matCellDef="let row"> {{row.progress}}% </td>
    </ng-container>

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

    <!-- Color Column -->
    <ng-container matColumnDef="color">
      <th mat-header-cell *matHeaderCellDef mat-sort-header> Color </th>
      <td mat-cell *matCellDef="let row" [style.color]="row.color"> {{row.color}} </td>
    </ng-container>

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

  <mat-paginator [pageSizeOptions]="[5, 10, 25, 100]"></mat-paginator>
</div>

还有你的ts文件：

import {Component, OnInit, ViewChild} from '@angular/core';
import {MatPaginator} from '@angular/material/paginator';
import {MatSort} from '@angular/material/sort';
import {MatTableDataSource} from '@angular/material/table';

export interface UserData {
  id: string;
  name: string;
  progress: string;
  color: string;
}

/** Constants used to fill up our data base. */
const COLORS: string[] = [
  'maroon', 'red', 'orange', 'yellow', 'olive', 'green', 'purple', 'fuchsia', 'lime', 'teal',
  'aqua', 'blue', 'navy', 'black', 'gray'
];
const NAMES: string[] = [
  'Maia', 'Asher', 'Olivia', 'Atticus', 'Amelia', 'Jack', 'Charlotte', 'Theodore', 'Isla', 'Oliver',
  'Isabella', 'Jasper', 'Cora', 'Levi', 'Violet', 'Arthur', 'Mia', 'Thomas', 'Elizabeth'
];

/**
 * @title Data table with sorting, pagination, and filtering.
 */
@Component({
  selector: 'table-overview-example',
  styleUrls: ['table-overview-example.css'],
  templateUrl: 'table-overview-example.html',
})
export class TableOverviewExample implements OnInit {
  displayedColumns: string[] = ['id', 'name', 'progress', 'color'];
  dataSource: MatTableDataSource<UserData>;

  @ViewChild(MatPaginator, {static: true}) paginator: MatPaginator;
  @ViewChild(MatSort, {static: true}) sort: MatSort;

  constructor() {
    // Create 100 users
    const users = Array.from({length: 100}, (_, k) => createNewUser(k + 1));

    // Assign the data to the data source for the table to render
    this.dataSource = new MatTableDataSource(users);
  }

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

  applyFilter(filterValue: string) {
    this.dataSource.filter = filterValue.trim().toLowerCase();

    if (this.dataSource.paginator) {
      this.dataSource.paginator.firstPage();
    }
  }
}

/** Builds and returns a new User. */
function createNewUser(id: number): UserData {
  const name = NAMES[Math.round(Math.random() * (NAMES.length - 1))] + ' ' +
      NAMES[Math.round(Math.random() * (NAMES.length - 1))].charAt(0) + '.';

  return {
    id: id.toString(),
    name: name,
    progress: Math.round(Math.random() * 100).toString(),
    color: COLORS[Math.round(Math.random() * (COLORS.length - 1))]
  };
}

将数据限制到某些页面可以防止在垂直或水平滚动时出现故障。