关闭或提交后如何丢弃或清除MatDailog数据

Question

我有一个名为customers(dialog window)的组件，其中有两个组件分别为 list 和 display ，来自 list 组件我将像这样将某些对象推入显示组件中的表：

组件代码：

list.component.html

<h3>List</h3>
<form [formGroup]="addListForm">
<mat-form-field>
  <mat-select  formControlName="CustomerIds" placeholder="Select Customer" multiple>
    <mat-option *ngFor="let customer of customers" [value]="customer" >
      {{customer.name}}
    </mat-option>
  </mat-select>
</mat-form-field>
<br>
<button  (click)="onAdd()">Add</button>
</form>

list.component.ts

import {Component,  OnInit } from '@angular/core';
import { FormBuilder,FormGroup } from '@angular/forms';
import { ContactService } from '../contacts.service';
import { MatOptionSelectionChange } from '@angular/material';
import { ICustomer } from '../models';
import { DataService } from '../data.service';

@Component({
  selector: 'app-list',
  templateUrl: './list.component.html',
  styleUrls: ['./list.component.css']
})
export class ListComponent implements OnInit {
public customers: ICustomer;
public someCustomer: ICustomer;
public addListForm: FormGroup;

constructor(private fb: FormBuilder,
  private myService: ContactService,
   public dataService: DataService) { }

  public async ngOnInit(): Promise<void> {
    this.addListForm = this.fb.group({
      CustomerIds: [null],
    });
    this.customers = await this.myService.getCustomers('');
  }
  public async selected(event: MatOptionSelectionChange, customer: ICustomer): Promise<void> {
    this.myService.onCustomerSelect.next(customer);
  }

    public onAdd(): void {
    this.someCustomer = this.addListForm.value;
    this.dataService.onSelectCustomer.next(this.someCustomer);
  }

}

display.component.html

<table mat-table [dataSource]="selectedCustomers?.CustomerIds" >
            .....
  </table>

display.component.ts

import {Component,  OnInit } from '@angular/core';
import { FormBuilder,FormGroup } from '@angular/forms';
import { ICustomer } from '../models';
import { DataService } from '../data.service';
@Component({
  selector: 'app-display',
  templateUrl: './display.component.html',
  styleUrls: ['./display.component.css']
})
export class DisplayComponent implements OnInit {
public  contacts: ICustomer;
public selectedCustomers: any;
public displayForm: FormGroup;
public addCustomer: any;

public displayedColumns: string[] = ['name', 'email', 'phone', 'button'];

constructor(private fb: FormBuilder,public dataService: DataService) { }

  public async ngOnInit(): Promise<void> {
    this.displayForm = this.fb.group({
    });
   this.dataService.onSelectCustomer.subscribe(value => {
   this.selectedCustomers = value;
  });
  }

}

现在，我将从 list 组件中将一些对象（客户）推送到 display 组件，然后我将关闭对话框窗口。如果再次打开对话框窗口，则表数据必须清除，而没有任何以前从 list 组件中推送的数据。如何清除表缓存？

Stackblitz DEMO

Answer 1

在主文件app.component.ts中，使用MatDialog的afterClosed()方法，每次关闭Dialog时，该方法都会被调用以清空表的旧数据。

public openAdd(): void {
  const dialogRef: MatDialogRef<CustomersComponent> = this.dialog.open(CustomersComponent, {
    width: '80vw', height: '80vh',
  });
  dialogRef.afterClosed().subscribe(result => {
    this.dataService.onSelectCustomer.next([]); 
  });
}

Answer 2

您认为与缓存无关。您正在使用Service在组件之间共享数据，因此将现有的推入值放入next()中，值或数据仍然可以使用。您可以阅读有关Services的更多信息。

因此，如果要清除现有数据，则有两种方法：

  

解决方案1：

如FarhatZaman所述，您可以订阅dialogRef.afterClosed（）方法：

dialogRef.afterClosed().subscribe(res => {
      this.dataService.onSelectCustomer.next([]);
 })

  

解决方案2：

您可以像这样清除方法中的数据：

public onSave(): void {
   this.addCustomer = this.selectedCustomers;
   this.dataService.onSelectCustomer.next([]); // Here
}

Stackblitz