为什么当我单击第二张图像时却没有弹出第一张图像？

Question

我试图弄清楚如何使第二个图像在单击时具有弹出效果。 第二张图片的代码与第一张图片完全相同，即使这样也不会产生相同的弹出效果。 对于我来自日本的英语不好，我感到抱歉。我会感谢一些帮助的人。

 #myImg { border-radius: 5px; cursor: pointer; transition: 0.3s; } #myImg:hover {opacity: 0.7;} /* The Modal (background) */ .modal { display: none; /* Hidden by default */ position: fixed; /* Stay in place */ z-index: 1; /* Sit on top */ padding-top: 100px; /* Location of the box */ left: 0; top: 0; width: 100%; /* Full width */ height: 100%; /* Full height */ overflow: auto; /* Enable scroll if needed */ background-color: rgb(0,0,0); /* Fallback color */ background-color: rgba(0,0,0,0.9); /* Black w/ opacity */ } /* Modal Content (image) */ .modal-content { margin: auto; display: block; width: 80%; max-width: 700px; } /* Caption of Modal Image */ #caption { margin: auto; display: block; width: 80%; max-width: 700px; text-align: center; color: #ccc; padding: 10px 0; height: 150px; } /* Add Animation */ .modal-content, #caption { -webkit-animation-name: zoom; -webkit-animation-duration: 0.6s; animation-name: zoom; animation-duration: 0.6s; } @-webkit-keyframes zoom { from {-webkit-transform:scale(0)} to {-webkit-transform:scale(1)} } @keyframes zoom { from {transform:scale(0)} to {transform:scale(1)} } /* The Close Button */ .close { position: absolute; top: 15px; right: 35px; color: #f1f1f1; font-size: 40px; font-weight: bold; transition: 0.3s; } .close:hover, .close:focus { color: #bbb; text-decoration: none; cursor: pointer; } /* 100% Image Width on Smaller Screens */ @media only screen and (max-width: 700px){ .modal-content { width: 100%; } } 

 <h2>Image Modal</h2> <p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p> <p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p> <img id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200"> <img id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200"> <!-- The Modal --> <div id="myModal" class="modal"> <span class="close">&times;</span> <img class="modal-content" id="img01"> <div id="caption"></div> </div> <script> // Get the modal var modal = document.getElementById('myModal'); // Get the image and insert it inside the modal - use its "alt" text as a caption var img = document.getElementById('myImg'); var modalImg = document.getElementById("img01"); var captionText = document.getElementById("caption"); img.onclick = function(){ modal.style.display = "block"; modalImg.src = this.src; captionText.innerHTML = this.alt; } // Get the <span> element that closes the modal var span = document.getElementsByClassName("close")[0]; // When the user clicks on <span> (x), close the modal span.onclick = function() { modal.style.display = "none"; } </script> 

Answer 1

您永远不要在不同的元素中设置相同的ID。 该ID应该是唯一的。 使用var img = document.getElementById('myImg'); 您仅选择第一个元素。

解

一种方法是将相同的类设置到两个元素。

<img class="images" id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200"> 
<img class="images" id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200">

现在，您可以使用getElementsByClassName获得这两个元素。

您将获得一个HTML集合，因此您需要将其解析为一个数组。

var imagesCollection = document.getElementsByClassName('images');
var imagesArray = Array.prototype.slice.call( imagesCollection );

最后一步是给它一个onclick处理程序的名称，以便您可以在map两个元素中进行设置

function imageOnClickHandler(){
  modal.style.display = "block";
  modalImg.src = this.src;
  captionText.innerHTML = this.alt;
}

imagesArray.map(function (img){
  img.onclick = imageOnClickHandler;
})

完整的源代码

 #myImg { border-radius: 5px; cursor: pointer; transition: 0.3s; } #myImg:hover {opacity: 0.7;} /* The Modal (background) */ .modal { display: none; /* Hidden by default */ position: fixed; /* Stay in place */ z-index: 1; /* Sit on top */ padding-top: 100px; /* Location of the box */ left: 0; top: 0; width: 100%; /* Full width */ height: 100%; /* Full height */ overflow: auto; /* Enable scroll if needed */ background-color: rgb(0,0,0); /* Fallback color */ background-color: rgba(0,0,0,0.9); /* Black w/ opacity */ } /* Modal Content (image) */ .modal-content { margin: auto; display: block; width: 80%; max-width: 700px; } /* Caption of Modal Image */ #caption { margin: auto; display: block; width: 80%; max-width: 700px; text-align: center; color: #ccc; padding: 10px 0; height: 150px; } /* Add Animation */ .modal-content, #caption { -webkit-animation-name: zoom; -webkit-animation-duration: 0.6s; animation-name: zoom; animation-duration: 0.6s; } @-webkit-keyframes zoom { from {-webkit-transform:scale(0)} to {-webkit-transform:scale(1)} } @keyframes zoom { from {transform:scale(0)} to {transform:scale(1)} } /* The Close Button */ .close { position: absolute; top: 15px; right: 35px; color: #f1f1f1; font-size: 40px; font-weight: bold; transition: 0.3s; } .close:hover, .close:focus { color: #bbb; text-decoration: none; cursor: pointer; } /* 100% Image Width on Smaller Screens */ @media only screen and (max-width: 700px){ .modal-content { width: 100%; } } 

 <h2>Image Modal</h2> <p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p> <p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p> <img class="images" id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200"> <img class="images" id="myImg" src="https://cdn.theatlantic.com/assets/media/img/mt/2017/06/GettyImages_675371680/lead_960.jpg?1498239007" alt="Trolltunga, Norway" width="300" height="200"> <link rel="stylesheet" href="/playground/modal.css"> <!-- The Modal --> <div id="myModal" class="modal"> <span class="close">&times;</span> <img class="modal-content" id="img01"> <div id="caption"></div> </div> <script> // Get the modal var modal = document.getElementById('myModal'); // Get the image and insert it inside the modal - use its "alt" text as a caption var imagesCollection = document.getElementsByClassName('images'); var imagesArray = Array.prototype.slice.call( imagesCollection ) var modalImg = document.getElementById("img01"); var captionText = document.getElementById("caption"); imagesArray.map(function (img){ img.onclick = imageOnClickHandler; }) function imageOnClickHandler(){ modal.style.display = "block"; modalImg.src = this.src; captionText.innerHTML = this.alt; } // Get the <span> element that closes the modal var span = document.getElementsByClassName("close")[0]; // When the user clicks on <span> (x), close the modal span.onclick = function() { modal.style.display = "none"; } </script> 

Answer 2

document.getElementById一次只能选择一个元素，您应该对元素使用唯一的ID。

为此，您想尝试的一件事是为img元素添加class="imgs" ，并使用选择器功能，例如document.querySelectorAll或document.getElementsByClassName 。 然后，您可以通过for循环为每个图像应用样式。

Answer 3

两个图像都具有相同的id ，即myImg ，这是错误的id应该是唯一的，将其更改为class并使用document.querySelectorAll而不是

document.getElementById