NgFormlink

说明link

As soon as you import the FormsModule, this directive becomes active by default on all <form> tags. You don't need to add a special selector.

只要你导入了 FormsModule，该指令就会默认在所有 <form> 标签上生效。你不需要再添加任何特殊的选择器。

You can export the directive into a local template variable using ngForm as the key (ex: #myForm="ngForm"). This is optional, but useful. Many properties from the underlying FormGroup instance are duplicated on the directive itself, so a reference to it will give you access to the aggregate value and validity status of the form, as well as user interaction properties like dirty and touched.

你可以以 ngForm 作为 key 把该指令导出到一个局部模板变量（如 #myForm="ngForm"）。这是可选的，但很有用。 来自本指令背后的 FormGroup 实例的很多属性，都被复制到了指令自身，所以拿到一个对该指令的引用就可以让你访问此表单的聚合值和验证状态， 还有那些用户交互类的属性，比如 dirty 和 touched。

To register child controls with the form, you'll want to use NgModel with a name attribute. You can also use NgModelGroup if you'd like to create sub-groups within the form.

如果要通过表单注册子控件，你还要使用一个带有 name 属性的 NgModel。你还可以使用 NgModelGroup 在表单中创建子组。

You can listen to the directive's ngSubmit event to be notified when the user has triggered a form submission. The ngSubmit event will be emitted with the original form submission event.

你可以监听该指令的 ngSubmit 事件，以便当用户触发了一次表单提交时得到通知。发出 ngSubmit 事件时，会携带原始的 DOM 表单提交事件。

In template driven forms, all <form> tags are automatically tagged as NgForm. If you want to import the FormsModule but skip its usage in some forms, for example, to use native HTML5 validation, you can add ngNoForm and the <form> tags won't create an NgForm directive. In reactive forms, using ngNoForm is unnecessary because the <form> tags are inert. In that case, you would refrain from using the formGroup directive.

在模板驱动表单中，所有 <form> 标签都会自动应用上 NgForm 指令。 如果你只想导入 FormsModule 而不想把它应用于某些表单中，比如，要想使用 HTML5 验证，你可以添加 ngNoForm 属性， 这样标签就不会在 <form> 上创建 NgForm 指令了。 在响应式表单中，则不需要用 ngNoForm，因为 NgForm 指令不会自动应用到 <form> 标签上，你只要别主动添加 formGroup 指令就可以了。

• npm package: @angular/forms

• NgModule: FormsModule