具有列值的材料表数据源过滤器

Question

如何过滤具有特定列的材料数据表？

 public dataSource;

this.dataSource = new MatTableDataSource(this.items);
        this.dataSource.filterPredicate = function customFilter(data , filter:string ): boolean {
            return (data.name.startsWith(filter));
        }

applyFilter(filterValue: string) {
    filterValue = filterValue.trim(); // Remove whitespace
    filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
    this.dataSource.filter = filterValue;
}

---

上面的代码不起作用，当我键入返回时，没有匹配的数据。

原文由 bereket gebredingle 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

从 文档。

例如数据对象{id: 123, name: ‘Mr. Smith’, favoriteColor: ‘blue’} 将减少到 123mr。史密斯布鲁。如果您的过滤器字符串是蓝色的，那么它将被视为匹配，因为它包含在缩减的字符串中，并且该行将显示在表中。

要覆盖默认过滤行为，可以设置自定义 filterPredicate 函数，该函数接受数据对象和过滤器字符串，如果数据对象被认为是匹配项，则返回 true。

如果您只想使用过滤器特定的列，您需要覆盖 filterPredicate 并且答案已经在 这里。

这是过滤的工作示例。

表过滤-example.html

 <div class="example-container mat-elevation-z8">
  <div class="example-header">
    <mat-form-field>
      <input matInput (keyup)="applyFilter($event.target.value)" placeholder="Filter">
    </mat-form-field>
  </div>

  <mat-table #table [dataSource]="dataSource">

    <!-- 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>

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

表过滤-example.ts

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

    /**
     * @title Table with filtering
     */
    @Component({
      selector: 'table-filtering-example',
      styleUrls: ['table-filtering-example.css'],
      templateUrl: 'table-filtering-example.html',
    })
    export class TableFilteringExample {
      displayedColumns = ['position', 'name', 'weight', 'symbol'];
      dataSource = new MatTableDataSource(ELEMENT_DATA);

      applyFilter(filterValue: string) {
        filterValue = filterValue.trim(); // Remove whitespace
        filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
        this.dataSource.filter = filterValue;
      }
    }

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

    const ELEMENT_DATA: Element[] = [
      {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'},
      {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'},
      {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'},
      {position: 11, name: 'Sodium', weight: 22.9897, symbol: 'Na'},
      {position: 12, name: 'Magnesium', weight: 24.305, symbol: 'Mg'},
      {position: 13, name: 'Aluminum', weight: 26.9815, symbol: 'Al'},
      {position: 14, name: 'Silicon', weight: 28.0855, symbol: 'Si'},
      {position: 15, name: 'Phosphorus', weight: 30.9738, symbol: 'P'},
      {position: 16, name: 'Sulfur', weight: 32.065, symbol: 'S'},
      {position: 17, name: 'Chlorine', weight: 35.453, symbol: 'Cl'},
      {position: 18, name: 'Argon', weight: 39.948, symbol: 'Ar'},
      {position: 19, name: 'Potassium', weight: 39.0983, symbol: 'K'},
      {position: 20, name: 'Calcium', weight: 40.078, symbol: 'Ca'}, ];

---

您可以使用 filterPredicate 过滤特定列，如下所示：

   ngOnInit() {
    this.dataSource.filterPredicate = (data: Element, filter: string) => {
      return data.name == filter;
     };
   }
 applyFilter(filterValue: string) {
    // filterValue = filterValue.trim(); // Remove whitespace
    // filterValue = filterValue.toLowerCase(); // MatTableDataSource defaults to lowercase matches
    this.dataSource.filter = filterValue;
  }

我已经更改了 applyFilter() 并添加了 ngOnInit() 。现在它只工作 名称 列和完全相同的值 (==)

原文由 krezus 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

app.compont.html

  <mat-form-field floatPlaceholder="never">
            <input matInput placeholder="Filter name" (keyup)="applyFilter($event.target.value)">
          </mat-form-field>
        <mat-table matSort  [dataSource]="dataSource" class="mat-elevation-z8">

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

            <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
            <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
          </mat-table>
          <mat-paginator [pageSize]="5" [pageSizeOptions]="[5, 10, 15]" showFirstLastButtons></mat-paginator>

app.component.ts

 import { Component, OnInit, ViewChild } from '@angular/core';
import { MatPaginator } from '@angular/material/paginator';
import { MatTableDataSource } from '@angular/material/table';
import { MatSort } from '@angular/material/sort';
export interface PeriodicElement {
  name: string;
  position: number;
  weight: number;
  symbol: string;
}

const ELEMENT_DATA: PeriodicElement[] = [
  { 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' },
  { 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' },
  { 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' },
];

@Component({
  selector: 'app-mat-table',
  templateUrl: './mat-table.component.html',
  styleUrls: ['./mat-table.component.css'],
})
export class MatTableComponent {
  displayedColumns: string[] = ['position', 'name', 'weight', 'symbol'];
  dataSource = new MatTableDataSource<PeriodicElement>(ELEMENT_DATA);

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

  ngOnInit() {
    this.dataSource.paginator = this.paginator;
    this.dataSource.sort = this.sort;
  }
  applyFilter(filterValue: string) {
    this.dataSource.filter = filterValue.trim().toLowerCase();
  }
}

原文由 Sushil 发布，翻译遵循 CC BY-SA 4.0 许可协议