MaxLengthValidator
该指令用于为带有 maxlength 属性的控件添加最大长度验证器。该指令会提供 NG_VALIDATORS 多重提供商列表。
A directive that adds max length validation to controls marked with the maxlength attribute. The directive is provided with the NG_VALIDATORS multi-provider list.
参见
NgModules
选择器
[maxlength][formControlName][maxlength][formControl][maxlength][ngModel]
属性
| 属性 | 说明 |
|---|---|
@Input() | Tracks changes to the the maximum length bound to this directive. |
说明
添加最大长度验证器
Adding a maximum length validator
下面的例子演示了如何为一个带有 ngModel 绑定的输入框添加最大长度验证器。
The following example shows how to add a maximum length validator to an input attached to an ngModel binding.
<input name="firstName" ngModel maxlength="25">
方法
A lifecycle method called when the directive's inputs change. For internal use only. | |||
参数
返回值
|
Method that validates whether the value exceeds the maximum length requirement. | |||
参数
返回值
|
Registers a callback function to call when the validator inputs change. |
