Question

我才刚开始接触Ngrx。我已经连接了各种控件以进行更新，然后从我的商店中返回数据。文本框和复选框可以按预期工作，但是组合框是另一层。我无法正确绑定。

这是我面临的问题：

1）当我更新组合框中的值时，setCurrentBadge函数被触发两次

2）我从组合框中的列表中选择的值称为 <Dialog PaperProps={{ component: PaperComponent, dialogRef: this.dialogRef }} >不可见。

3）触发getCurrentBadge函数，即使该函数位于ngInit生命周期挂钩中并且页面尚未重新加载。

4）重新加载页面时，会触发getCurrentBadge函数，但组合框不会显示返回的值。

就代码而言，当组合框的值更改时，我需要badgeCodeSelected（$ event）触发一次。我需要[value] =“ selectedBadge”来显示选定的值，并且在重新加载页面时，我需要组合框来显示从商店返回的值）

这是我的代码。

<mat-select class="badge-codes-combobox">

    <div class="row">
  <div class="col-md-4">
    <app-declaration-type
    [errorMessage] = "errorMessage$ | async"
    [displayTypes] = "displayTypes$ | async"
    [declarationTypes] = "declarationTypes$ | async"
    [badges] = "badges$ | async"
    [traderReference]= "traderReference$ | async"
    [selectedBadge] = "selectedBadge$ | async"
    (badgeSelected) = "badgeCodeSelected($event)" 
    (checked) = "checkChanged($event)"
    (traderReferenceSet) = "onBlurTraderReferenceChange($event)"
    >
    </app-declaration-type>
  </div>
</div>

@Component({
  selector: 'app-declaration',
  templateUrl: './declaration-shell.component.html',
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class DeclarationShellComponent implements OnInit {
  errorMessage$: Observable<string>;
  displayTypes$: Observable<boolean>;
  declarationTypes$: Observable<Declarationtype[]>;
  badges$: Observable<Badge[]>;
  selectedDeclarationType$: Observable<string>;
  selectedBadge$: Observable<Badge>;
  traderReference$: Observable<string>;

  constructor(private store: Store<fromDeclaraionType.State>) {}

  ngOnInit() {
    this.store.dispatch(new fromDeclarationTypeActions.LoadDeclarationType());
    this.store.dispatch(new fromDeclarationTypeActions.LoadBadges());

    this.errorMessage$ = this.store.pipe(select(fromDeclaraionType.getError));
    this.displayTypes$ = this.store.pipe(
      select(fromDeclaraionType.getToggleDeclarationTypes)
    );
    this.declarationTypes$ = this.store.pipe(
      select(fromDeclaraionType.getDeclarationTypes)
    );

    this.selectedDeclarationType$ = this.store.pipe(
      select(fromDeclaraionType.getCurrentDeclarationType)
    );

    this.badges$ = this.store.pipe(select(fromDeclaraionType.getBadges));

    this.selectedBadge$ = this.store.pipe(
      select(fromDeclaraionType.getCurrentBadge),
      tap(x => console.log('About to fetch current badge from store {0}', x))
    );

    this.traderReference$ = this.store.pipe(
      select(fromDeclaraionType.getTraderReference)
    );
  }

  checkChanged(value: boolean): void {
    console.log('About to dispatch toggle Display Declaration Types');
    this.store.dispatch(
      new fromDeclarationTypeActions.ToggleDeclarationTypes(value)
    );
  }

  onBlurTraderReferenceChange(value: string) {
    console.log('About to dispatch Set Trader Reference');
    this.store.dispatch(
      new fromDeclarationTypeActions.SetTraderReference(value)
    );
  }

  badgeCodeSelected(value: Badge) {
    console.log('About to dispatch Set Current Badge');
    console.log(value);
    this.store.dispatch(new fromDeclarationTypeActions.SetCurrentBadge(value));
  }
}

 <div class="declaration-type">
  <mat-accordion>
    <mat-expansion-panel
      [expanded]="displayTypes === true"
      (opened)="(displayTypes === true)"
    >
      <mat-expansion-panel-header
        [collapsedHeight]="customCollapsedHeight"
        [expandedHeight]="customExpandedHeight"
      >
        <mat-panel-title> <h4>Declaration Type</h4> </mat-panel-title>
        <label>
          <input
            class="form-check-input"
            type="checkbox"
            (change)="checkChanged($event.target.checked)"
            [checked]="displayTypes"
          />
          Display Types?
        </label>
      </mat-expansion-panel-header>

      <div class="controls-wrapper">
        <div class="flex-container">
          <div class="flex-item-declarationType">
            <label class="field-label labelAlignment">
              Decln Type [01]:
              <mat-select class="declaration-type-combobox" [value]="selectedDeclarationType">
                <mat-option
                  *ngFor="let declarationType of declarationTypes"
                  [value]="declarationType?.value"

                >
                  {{ declarationType.value }}
                </mat-option>
              </mat-select>
            </label>
          </div>
          <div class="flex-item-badgeCode">
            <label class="field-label labelAlignment">
              Badge Codes:
              <mat-select class="badge-codes-combobox" [value]="selectedBadge" >
                <mat-option (onSelectionChange)="badgeCodeSelected(badge)"
                  *ngFor="let badge of badges"
                  [value]="badge?.code">
                 <div>{{ badge.code }} - {{ badge.name }}</div>
                </mat-option>
              </mat-select>
            </label>
          </div>
        </div>
        <div class="flex-container">
          <div class="flex-item-traderReference">
            <label class="field-label labelAlignment">
              Trader Reference [07]:
              <input
                matInput
                type="text"
                [(ngModel)]="traderReference"
                class="trader-reference-inputBox"
                (blur)="onTraderReferenceSet(traderReference)"
              />
              <button
                mat-button
                *ngIf="traderReference"
                matSuffix
                mat-icon-button
                aria-label="Clear"
                (click)="traderReferenceValue = ''"
              >
                <mat-icon>close</mat-icon>
              </button>
            </label>
          </div>
        </div>
      </div>
    </mat-expansion-panel>
  </mat-accordion>
</div>

Answer 1

这对您来说将是一个转变，但是我想分享一下我拥有一个库，该库除其他外还具有将表单控件绑定到商店的内置指令。最大的变化是，您需要构建StoreObject而不是使用选择器，并且您将不会编写或处理任何操作。

该库称为ng-app-state，绑定到表单控件的键在nasModel指令中。我会在下面给你一个想法。

假设您的复选框的值位于商店中这样的位置：

class DeclarationTypeState {
  badgeCode: string;
}

然后您将像这样使用它：

@Component({
  template: `
    <mat-select [nasModel]="badgeCodeStore">
      <mat-option ...></mat-option>
    </mat-select>
  `,
})
export class DeclarationTypeComponent {
  badgeCodeStore: StoreObject<string>;

  constructor(myStore: MyStore) {
    this.badgeCodeStore = myStore('keyForDeclarationTypeState')('badgeCode');
  }
}

这将对您的商店进行两向绑定，以使mat-select与商店保持同步，并在用户更改商店名称时对其进行编辑。

从物料组合框中更新Ngrx存储，然后绑定到返回的ngrx存储数据

1 个答案: