SelectMultipleControlValueAccessor
The ControlValueAccessor for writing multi-select control values and listening to multi-select control changes. The value accessor is used by the FormControlDirective, FormControlName, and NgModel directives.
参见
NgModules
选择器
select[multiple][formControlName]select[multiple][formControl]select[multiple][ngModel]
属性
| 属性 | 说明 |
|---|---|
value: any | The current value |
onChange: (_: any) => { } | The registered callback function called when a change event occurs on the input element. |
onTouched: () => { } | The registered callback function called when a blur event occurs on the input element. |
@Input() | Write-only. Tracks the option comparison algorithm for tracking identities when checking for changes. |
说明
Using a multi-select control
The follow example shows you how to use a multi-select control with a reactive form.
const countryControl = new FormControl();
<select multiple name="countries" [formControl]="countryControl">
<option *ngFor="let country of countries" [ngValue]="country">
{{ country.name }}
</option>
</select>
Customizing option selection
To customize the default option comparison algorithm, <select> supports compareWith input. See the SelectControlValueAccessor for usage.
方法
Sets the "value" property on one or of more of the select's options. |
Registers a function called when the control value changes and writes an array of the selected options. |
Registers a function called when the control is touched. |
Sets the "disabled" property on the select input element. |
