文本字段 Text field

text-field 包为用来处理文本输入字段（如 <input> 和 <textarea> 提供了一些很有用的实用工具。

The text-field package provides useful utilities for working with text input fields such as <input> and <textarea>.

link 自动调整 <textarea> 的大小

link Automatically resizing a <textarea>

cdkTextareaAutosize 指令可以应用在任何 <textarea> 上，以便让它自动根据内容调整大小。要扩展的最小和最大行数可以分别通过 cdkAutosizeMinRows 和 cdkAutosizeMaxRows 属性来设置。

The cdkTextareaAutosize directive can be applied to any <textarea> to make it automatically resize to fit its content. The minimum and maximum number of rows to expand to can be set via the cdkAutosizeMinRows and cdkAutosizeMaxRows properties respectively.

调用 resizeToFitContent 可以通过编程的方式触发调整大小的逻辑。该方法接受一个默认为 false 的可选逻辑参数 force。传入 true 就会强制 <textarea> 调整大小（即使文本内容没有改变）。当影响 <textarea> 的一些样式发生变化时，这很有用。

The resize logic can be triggered programmatically by calling resizeToFitContent. This method takes an optional boolean parameter force that defaults to false. Passing true will force the <textarea> to resize even if its text content has not changed, this can be useful if the styles affecting the <textarea> have changed.

link 监控 <input> 的自动填充状态

link Monitoring the autofill state of an <input>

AutofillMonitor 是一个可注入的服务，它允许用户监控 <input> 的自动填充状态。它有一个 monitor 方法，可以接受一个要监视的元素，并返回带有 target 和 isAutofilled 属性的 Observable。每当指定 <input> 的自动填充状态发生变化时，该可观察对就会发出事件。你所监控的任何元素最终都应该通过调用 stopMonitoring ，并传入同一个元素来停止监控。

The AutofillMonitor is an injectable service that allows the user to monitor the autofill state of an <input>. It has a monitor method that takes an element to monitor and returns an Observable of autofill event objects with a target and isAutofilled property. The observable emits every time the autofill state of the given <input> changes. Any element you monitor should eventually be unmonitored by calling stopMonitoring with the same element.

为了简化这个过程，还有一个 cdkAutofill 指令可以自动处理监控与停止监控，并在自动填充状态发生变化时作为 @Output 绑定发出事件。

To simplify this process, there is also a cdkAutofill directive that automatically handles monitoring and unmonitoring and doubles as an @Output binding that emits when the autofill state changes.

注意：当自动填充状态发生变化时，这项服务会需要一些 CSS 来安装动画钩子。如果你正在使用 Angular Material，那么这个 CSS 就已经作为 mat-core mixin 的一部分提供了。如果你没有使用 Angular Material，就应该用 cdk-text-field mixin 来包含这个 CSS。

Note: This service requires some CSS to install animation hooks when the autofill statechanges. If you are using Angular Material, this CSS is included as part of the mat-core mixin. If you are not using Angular Material, you should include this CSS with the cdk-text-field mixin.

@import '~@angular/cdk/text-field/text-field'; 

@include cdk-text-field();

link 为 <input> 的自动填充状态设置样式

link Styling the autofill state of an <input>

在自动填充的 <input> 上覆盖浏览器的默认 background 和 color 属性可能会很困难。为了简单起见，CDK 包含了一个 mixin cdk-text-field-autofill-color，它可以用来设置这些属性。它以第一个参数 background 和第二个可选参数 color 的值作为参数。

It can be difficult to override the browser default background and color properties on an autofilled <input>. To make this simpler, the CDK includes a mixin cdk-text-field-autofill-color which can be used to set these properties. It takes a background value as the first parameter and an optional color value as the second parameter.

@import '~@angular/cdk/text-field/text-field'; 

// Set custom-autofill inputs to have no background and red text.
input.custom-autofill {
  @include cdk-text-field-autofill-color(transparent, red);
}