javascript - 错误 TS2554：预期 3-4 个参数，但得到 5

问题描述

我的指令低于错误。当我将鼠标悬停在文本上时，我只想显示颜色。

更好的highlight.directive.ts

import { Directive, OnInit, ElementRef, HostListener, Renderer2 } from '@angular/core';

@Directive({
  selector: '[appBetterHighlight]'
})
export class BetterHighlightDirective implements OnInit{

  constructor(private elRef: ElementRef, private rederer: Renderer2) { }

  ngOnInit() {
    // this.rederer.setStyle(this.elRef.nativeElement, 'background-color', 'blue', false, false);
  }

  @HostListener('mouseenter') mouseOver(eventData: Event) {
    this.rederer.setStyle(this.elRef.nativeElement, 'background-color', 'blue', false, false);
  }

  @HostListener('mouseenter') mouseleave(eventData: Event) {
    this.rederer.setStyle(this.elRef.nativeElement, 'background-color', 'transparent', false, false);
  }
}

基本高亮directive.ts

import { Directive, ElementRef, OnInit } from '@angular/core';

@Directive({
    selector: '[appBasicHighlight]'
})
export class BasicHighLightDirective implements OnInit {
    constructor(private elementRef: ElementRef) {

    }

    ngOnInit(){
        this.elementRef.nativeElement.style.backgroundColor = 'green';
    }
}

app.component.ts

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  oddNumbers = [1, 3, 5];
  evenNumbers = [2, 4];
  onlyOdd = false;
}

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';
import { BasicHighLightDirective } from './basic-highlight/basic-highlight-directive';
import { BetterHighlightDirective } from './better-highlight/better-highlight.directive';

@NgModule({
  declarations: [
    AppComponent,
    BasicHighLightDirective,
    BetterHighlightDirective
  ],
  imports: [
    BrowserModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.html

<div class="container">
  <div class="row">
    <div class="col-xs-12">
      <button class="btn btn-primary" (click)="onlyOdd = !onlyOdd">Show Numbers</button>
      <br><br>

      <ul class="list-group">
        <div *ngIf="onlyOdd">
          <li class="list-group-item" 
              [ngClass]="{odd: odd % 2 !== 0}" 
              [ngStyle]="{backgroundColor: even % 2 !== 0 ? 'yellow' : 'transparent'}"
              *ngFor="let odd of oddNumbers">
            {{ odd }}
          </li>
        </div>

        <div *ngIf="!onlyOdd">
          <li class="list-group-item" 
              [ngClass]="{odd: even % 2 !== 0}" 
              [ngStyle]="{backgroundColor: even % 2 !== 0 ? 'yellow' : 'transparent'}"
              *ngFor="let even of evenNumbers">
            {{ even }}
          </li>
        </div>
      </ul>

      <p appBasicHighlight>Style me with basic directive!</p>
      <p appBetterHighlight>Style me with a Better directive!</p>
    </div>
  </div>
</div>

标签： javascriptangular7

您好，您使用 setStyle 错误。

    this.rederer.setStyle(this.elRef.nativeElement, 'background-color', 'blue');

只有 4 个参数而不是 5 个。 https://angular.io/api/core/Renderer2#setStyle

抽象 setStyle(el: any, style: string, value: any, flags?: RendererStyleFlags2): void 参数

1] el any 元素。

2] style string 样式
的名称。

3] value any 新值。

4] 可选标志 RendererStyleFlags2 样式变化的标志。默认情况下不设置任何标志。

选修的。默认未定义。

javascript - 错误 TS2554：预期 3-4 个参数，但得到 5

问题描述

解决方案

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