1、场景：

封装的_disabled指令，希望对它直接赋值使用，不想写个_disable指令，再传个参数来进行赋值。

<input nz-input type="string" placeholder="" name="sysOs" maxlength="100" _disable [disabled]="true">
<input nz-input type="string" placeholder="" name="sysOs" maxlength="100" [_disabled]="true">

实现：将指令名称 selector: '[_disabled]', 和参数设置的字符串保持一致，对它进行赋值时，即可进行一些操作。

@Input('_disabled') set condition(_disabled: boolean) {
    this.__disabled =_disabled;
    this._setDisabled();
  };

import {Directive,Input,ElementRef,Renderer2,AfterViewInit,
} from '@angular/core';@Directive({selector: '[_disabled]',
})export class DisabledDirective implements AfterViewInit {constructor(private el: ElementRef,private renderer2: Renderer2) {}private __disabled: boolean; // 私有化中间变量@Input('_disabled') set condition(_disabled: boolean) {this.__disabled =_disabled;this._setDisabled();};/*** 设置_disabled的状态和样式*/private _setDisabled() {if (this.nativeEl && this.renderer2) {if (this.__disabled) {this.renderer2.addClass(this.nativeEl, 'ant-input-disabled');this.renderer2.setAttribute(this.nativeEl, 'disabled', 'disabled');} else {this.renderer2.removeClass(this.nativeEl, 'ant-input-disabled');this.renderer2.removeAttribute(this.nativeEl, 'disabled');}}}ngAfterViewInit() {this._setDisabled();}// 缓存当前domnativeEl = this.el.nativeElement;
}