canDeactivate 不适用于 Angular 材质模态窗口

Question

我成功构建了 canDeactivate 守卫，它在正常 confirm 下工作正常，但我想用角度材料对话框来实现它，在这里我遇到了一些问题。

这是我的守卫：

@Injectable()
export class CanDeactivateGuard implements CanDeactivate<CreateQuoteComponent> {
  constructor(
    public dialog: MatDialog,
  ){

  }
  canDeactivate(component: CreateQuoteComponent): boolean {
    if (!component.changesSaved) {
      return component.confirmDialog();
      //return confirm('You have not saved your current work. Do you want to proceed and discard your changes?');
    }
    return true;
  }
}

这是我组件中的一个函数：

confirmDialog(): boolean {
    const message = 'You have not saved your current work. Do you want to proceed and discard?';
    const data = { 'message': message, 'toShowCancel': true, 'buttonYesCaption': 'Yes', 'buttonNoCaption': 'No' };
    const dialogRef = this.dialog.open(YesNoComponent, {
      width: '600px',
      height: '250px',
      data: data
    });
    dialogRef.afterClosed().subscribe(result=>{
      this.dialogRef1=result;
      return this.dialogRef1;
    });
    return this.dialogRef1;
  }

 I defined a boolean variable dialogRef1 at the top of the component.

它是带有模态窗口的组件的一部分：

onCloseClick(){
    this.dialogRef.close(false);
  }

  onSubmit(){
    this.dialogRef.close(true);
  }

我试图实现这个例子： How to send return value to CanDeactivate Guard after close the mat-dialog | Angular CanDeactivate Guard | Angular Material Dialog

但这对我不起作用，或者我做错了。提前致谢！

Answer 1

您正在返回一个变量值，该变量值由 Observable [即dialogRef.afterClosed()] 设置，这将由用户决定。您应该执行以下操作：

首先，将canDeactivate 的返回类型更改为Observable<boolean>，如下所示：

@Injectable()
export class CanDeactivateGuard implements CanDeactivate<CreateQuoteComponent> {
  constructor(
    public dialog: MatDialog,
  ){

  }
  canDeactivate(component: CreateQuoteComponent): Observable<boolean> {
    if (!component.changesSaved) {
      return component.confirmDialog();      
    }
    //please import 'of' form 'rxjs/operators'
    return of(true);
  }
}

现在让我们更改component.confirmDialog 方法以返回dialogRef.afterClosed() observable，如下所示：

confirmDialog(): Observable<boolean> {
    const message = 'You have not saved your current work. Do you want to proceed and discard?';
    const data = { 'message': message, 'toShowCancel': true, 'buttonYesCaption': 'Yes', 'buttonNoCaption': 'No' };
    const dialogRef = this.dialog.open(YesNoComponent, {
      width: '600px',
      height: '250px',
      data: data
    });
    return dialogRef.afterClosed();
  }

希望对你有帮助。