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我正在构建一个使用角度形式的角度应用程序。它适用于 angular 5 和 angular 6。但是当我通过 ng build -prod 部署它时，它会给出错误

在此处输入图像描述

这是我的登录组件代码

<form class="md-float-material form-material" [formGroup]="loginForm" (ngSubmit)="onSubmit()">
    <div class="text-center">
        <img src="../../assets/images/logo.png" alt="logo.png">
    </div>
    <div class="auth-box card">
        <div class="card-block">
            <div class="row m-b-20">
                <div class="col-md-12">
                    <h3 class="text-center">User Login</h3>
                </div>
            </div>
            <div class="form-group form-primary">
                <label for="username">Username</label>
                <input type="text" formControlName="username" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.username.errors }" />
                <div *ngIf="submitted && f.username.errors" class="invalid-feedback">
                    <div *ngIf="f.username.errors.required">Username is required</div>
                </div>
            </div>
            <div class="form-group form-primary">
                <label for="password">Password</label>
                <input type="password" formControlName="password" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.password.errors }" />
                <div *ngIf="submitted && f.password.errors" class="invalid-feedback">
                    <div *ngIf="f.password.errors.required">Password is required</div>
                </div>
            </div>
            <div class="form-group form-primary">
                <button class="btn btn-primary btn-md btn-block waves-effect waves-light text-center m-b-20">Login</button>
            </div>
            <div class="row">
                <div class="col-md-2">
                    <img src="../../assets/images/Logo-small-bottom.png" alt="small-logo.png">
                </div>
            </div>
        </div>
    </div>
</form>

这是 TS 代码

import { Component, OnInit } from '@angular/core';
import { Router, ActivatedRoute } from '@angular/router';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { AlertService, UserService } from '../_services';

@Component({ templateUrl: 'login.component.html' })
export class LoginComponent implements OnInit {
    loginForm: FormGroup;
    returnUrl: string;
    selectedValue: 'observer';

    constructor(
        public formBuilder: FormBuilder,
        public route: ActivatedRoute,
        public router: Router,
        public userService: UserService,
        public alertService: AlertService) { }

    public ngOnInit() {
        this.loginForm = this.formBuilder.group({
            username: ['', Validators.required],
            password: ['', Validators.required],
        });

        this.userService.logout();

        this.returnUrl = this.route.snapshot.queryParams['returnUrl'] || '/';
    }

    get f() { return this.loginForm.controls; }

    public onSubmit() {

        if (this.loginForm.invalid) {
            return;
        }


        this.userService.login(this.loginForm.value)
            .subscribe(
                response => {
                    this.alertService.success('User Authenticated', true);
                },
                error => this.alertService.error(error, false)
            );
    }
}
4

2 回答 2

1

此错误是 AoT(Ahead of Time) 编译的结果。

运行“ng serve”时没有出现这些错误的原因是ng serve执行了 JiT（Just in Time）编译。

在 AoT 编译中，您必须声明每个方法/变量以及许多其他内容。

一旦你在你的 ts 上定义了缺失的变量（比如在 LoginComponent 上提交），这些错误就会消失。

于 2019-02-07T01:33:32.533 回答
0

在这种特定情况下，我将在我们的类中创建一个 FormControl 实例。例如 loginForm = new FormControl();

这是对您的问题的一个很好的解释： https ://www.concretepage.com/angular-2/angular-2-formcontrol-example

于 2019-08-26T02:27:30.053 回答