JavaScript 單擊更改背景圖像？

Question

我正在嘗試使用一些基本的 JS 函數來更改我的 HTML 文檔上的正文背景。 我已將 function 設置為針對特定 ID，然后設置 style.background 標簽，如果是當前背景圖像，則將其設置為我指定的另一個，否則保持相同的圖像。 我現在已經無數次嘗試更改代碼，但似乎仍然無法更改背景。 對此的任何幫助將不勝感激。

HTML：

<div class="bg-image" 
     style="background-image: url('./img/frankie.jpg');
            height: 100vh" id="bacgr"> <!--SETS BACKGROUND using id tag to change w/ JS-->
        <main role="main" class="container d-flex justify-content-center">

          <div class="starter-template">
            <h1>Bootstrap starter template</h1>
            <p class="lead">Use this document as a way to quickly start any new project.<br> All you get is this text and a mostly barebones HTML document.</p>
          </div>

        </main>
    </div>

JS：

let myImage = document.getElementById('bacgr').style.backgroundImage; //have to target specific image(like an array ([0])), put inside div w/ id.

myImage.onclick = function() {
    if(myImage === "url('./img/frankie.jpg')") {
      myImage == "url('./img/jesus_mobile.jpg')";
    } else {
      myImage == "url('./img/frankie.jpg')";
    }
}

Answer 1

嘗試這個：

const el = document.getElementById('bacgr');
el.onclick = function() {
  if(this.style.backgroundImage === "url('./img/frankie.jpg')") {
    this.style.backgroundImage = "url('./img/jesus_mobile.jpg')";
  } else {
    this.style.backgroundImage = "url('./img/frankie.jpg')";
  }
}

這是示例

Answer 2

您只更改 URL，但不會將其分配回 dom 元素。

 const el = document.getElementById('bacgr'); let prev = 'url("https://images.unsplash.com/photo-1570215171323-4ec328f3f5fa")'; el.onclick = function() { el.style.backgroundImage = prev === el.style.backgroundImage? 'url("https://images.unsplash.com/photo-1583508915901-b5f84c1dcde1")': prev; }

 <div class="bg-image" style="background-image: url('https://images.unsplash.com/photo-1570215171323-4ec328f3f5fa'); height: 100vh" id="bacgr"> <main role="main" class="container d-flex justify-content-center"> <div class="starter-template"> <h1>Bootstrap starter template</h1> <p class="lead">Use this document as a way to quickly start any new project.<br> All you get is this text and a mostly barebones HTML document.</p> </div> </main> </div>