如果在表单标签中使用ngModel，则必须设置name属性，或者在ngModelOptions中定义表单控件为 "独立"。

Question

我使用的是angular 9.我的目的是当我点击登录按钮时，如果登录成功就会重定向到meto dashboard，否则就会重定向到登录页面，当我输入我的用户名和密码并点击登录按钮时就会显示错误。

tag, either the name attribute must be set or the form
      control must be defined as 'standalone' in ngModelOptions.

      Example 1: <input [(ngModel)]="person.firstName" name="first">
      Example 2: <input [(ngModel)]="person.firstName" [ngModelOptions]="{standalone: true}">
     at Function.push../node_modules/@angular/forms/fesm5/forms.js.TemplateDrivenErrors.missingNameException
(forms.js:4830)
    at NgModel.push../node_modules/@angular/forms/fesm5/forms.js.NgModel._checkName
(forms.js:5158)
    at NgModel.push../node_modules/@angular/forms/fesm5/forms.js.NgModel._checkForErrors
(forms.js:5143)
    at NgModel.push../node_modules/@angular/forms/fesm5/forms.js.NgModel.ngOnChanges
(forms.js:5046)
    at checkAndUpdateDirectiveInline (core.js:22777)
    at checkAndUpdateNodeInline (core.js:31612)
    at checkAndUpdateNode (core.js:31574)     at debugCheckAndUpdateNode (core.js:32211)
    at debugCheckDirectivesFn (core.js:32171)
    at Object.eval [as updateDirectives] (LoginComponent.html:16) View_LoginComponent_0 @ LoginComponent.html:15 LoginComponent.html:16
ERROR CONTEXT DebugContext_
loginc.component.html

---

编码

<div class="app-body">
    <main class="main d-flex align-items-center">
        <div class="container">
            <div class="row">
            <div class="col-md-8 mx-auto">
                <div class="card-group">
                <div class="card p-4">
                    <div class="card-body">
                    <form>
                        <h1>Login</h1>
                        <p class="text-muted">Sign In to your account</p>
                        <div class="input-group mb-3">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="icon-user"></i></span>
                        </div>
                        <input type="text" class="form-control" placeholder="Username" [(ngModel)]="username" autocomplete="username" required>
                        </div>
                        <div class="input-group mb-4">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="icon-lock"></i></span>
                        </div>
                        <input type="password" class="form-control" placeholder="Password"[(ngModel)]="password" autocomplete="current-password" required>
                        </div>
                        <div class="row">
                        <div class="col-6">
                            <button type="button" (click)=dologin class="btn btn-primary px-4">Login</button>
                        </div>
                        <div class="col-6 text-right">
                            <button type="button" class="btn btn-link px-0">Forgot password?</button>
                        </div>
                        </div>
                    </form>
                    </div>
                </div>
                <div class="card text-white bg-primary py-5 d-md-down-none" style="width:44%">
                    <div class="card-body text-center">
                    <div>
                        <h2>Sign up</h2>
                        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</p>
                        <button type="button" class="btn btn-primary active mt-3">Register Now!</button>
                    </div>
                    </div>
                </div>
                </div>
            </div>
            </div>
        </div>
    </main>
</div>

Answer 1

如果您使用 [(ngModel)] 像这样，你将需要设置 [ngModelOptions]="{standalone: true}"

<div class="app-body">
    <main class="main d-flex align-items-center">
        <div class="container">
            <div class="row">
            <div class="col-md-8 mx-auto">
                <div class="card-group">
                <div class="card p-4">
                    <div class="card-body">
                    <form>
                        <h1>Login</h1>
                        <p class="text-muted">Sign In to your account</p>
                        <div class="input-group mb-3">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="icon-user"></i></span>
                        </div>
                        <input type="text" class="form-control" placeholder="Username" [(ngModel)]="username" [ngModelOptions]="{standalone: true}" autocomplete="username" required>
                        </div>
                        <div class="input-group mb-4">
                        <div class="input-group-prepend">
                            <span class="input-group-text"><i class="icon-lock"></i></span>
                        </div>
                        <input type="password" class="form-control" placeholder="Password"[(ngModel)]="password" [ngModelOptions]="{standalone: true}" autocomplete="current-password" required>
                        </div>
                        <div class="row">
                        <div class="col-6">
                            <button type="button" (click)=dologin class="btn btn-primary px-4">Login</button>
                        </div>
                        <div class="col-6 text-right">
                            <button type="button" class="btn btn-link px-0">Forgot password?</button>
                        </div>
                        </div>
                    </form>
                    </div>
                </div>
                <div class="card text-white bg-primary py-5 d-md-down-none" style="width:44%">
                    <div class="card-body text-center">
                    <div>
                        <h2>Sign up</h2>
                        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</p>
                        <button type="button" class="btn btn-primary active mt-3">Register Now!</button>
                    </div>
                    </div>
                </div>
                </div>
            </div>
            </div>
        </div>
    </main>
</div>

更多信息在这里。https:/angular.ioapiformsNgModel。