import { Component, Directive, HostListener, ElementRef } from ‘@angular/core‘
@Directive({
selector: ‘[input-trim]‘,
host: {
‘(keyup)‘: ‘keyUpFunc($event.target)‘,
‘(click)‘: ‘onClick($event.target)‘,
‘role-data‘: ‘input-trim‘
}
})
export class InputTrimDirective {
private _elementRef: ElementRef
constructor(_elementRef: ElementRef) {
console.log(_elementRef, "获取挂载属性的DOM")
this._elementRef = _elementRef
}
/**
* 是属性装饰器，用来为宿主元素添加事件监,类似于我们原生JavaScript的addEventListener
@HostListener这里我们监听了keyup事件(可以定义原生JavaScript中的其他事件),
当表单中有输入的时候我们就会调用方法，传递了一个$event对象进去，后面紧跟我们触法keyup事件的方法体
可以用 @Component 中的 host 代替
* */
// @HostListener(‘keyup‘, [‘$event.target‘])
keyUpFunc(evt) {
if(evt.value) {
this._elementRef.nativeElement.value = evt.value + ‘_num‘
}
}
onClick(evt) {
console.log(evt.innerHTML, "click_div")
if(evt.innerHTML) {
this._elementRef.nativeElement.innerHTML = evt.innerHTML + ‘_num‘
}
<div>
<h1>指令---directive</h1>
<input type="text" class="input_1" input-trim>
<div class="click_div" input-trim>sasas</div>
<input type="text" class="input_2" role-data=‘input-trim‘>
</div>
import { BrowserModule } from ‘@angular/platform-browser‘;
import { NgModule } from ‘@angular/core‘;
import { AppRoutingModule } from ‘./app-routing.module‘;
import { AppComponent } from ‘./app.component‘;
import { TemplateDirective } from ‘./directive/template-directive.component‘
// 指令
import { InputTrimDirective } from ‘./directive/template-directive.component‘
@NgModule({
// 引入组件，指令
declarations: [
AppComponent,
TemplateDirective,
InputTrimDirective
],
imports: [
BrowserModule,
AppRoutingModule
],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule { }
