如何使用Javascript

时间：2017-05-29 11:51:19

标签： javascript html css

我正在处理一个网络项目，需要制作图片库。点击时图像需要放大。但是我的代码只有第一张图片放大。

如何让所有这些变焦 以下是我的源代码。

<!DOCTYPE html>
<html>
<head>
<style>
#myImg {
    border-radius: 5px;
    cursor: pointer;
    transition: 0.3s;
}

#myImg:hover {opacity: 0.7;}
.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)}
}

.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;
}

@media only screen and (max-width: 700px){
    .modal-content {
        width: 100%;
    }
}
</style>
</head>
<body>

<img id="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">
<img id="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">

<!-- The Modal -->
<div id="myModal" class="modal">
  <span class="close" id="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");
 function openModal(){
    modal.style.display = "block";
    modalImg.src = this.src;
    captionText.innerHTML = this.alt;
}

// Get the <span> element that closes the modal
var span = document.getElementById('close');

// When the user clicks on <span> (x), close the modal
 function close() { 
    modal.style.display = "none";
}
span.addEventListener("click", close);
img.addEventListener("click", openModal);
</script>

</body>
</html>

5 个答案:

答案 0 :(得分：2)

id名称在整个网页中必须是唯一的。否则，选择器仅适用于第一个。

让选择器处理多个元素，发明classes。您应该将代码更改为：

[...]
<img id="myImg1" class="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">
<img id="myImg2" class="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">
[...]

CSS：

[...]
.myImg {
     border-radius: 5px;
    cursor: pointer;
    transition: 0.3s;
}

.myImg:hover {opacity: 0.7;}
.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 */
}
[...]

注意我是如何更改点（#）的哈希值（.）。

哈希表示按id选择，点表示按类选择。对于一切，你应该遵循同样的原则。 Id什么时候是唯一的，什么时候是多个。

现在我们将在JS中按类选择：

/*[...]*/
// Select all the images by class
var imgs = document.querySelectorAll('.myImg');

// Loop the array and add the logic to each one
imgs.forEach(function(img) {
    img.addEventListener("click", openModal);
});
/*[...]*/

答案 1 :(得分：0)

不要使用ID使用类。例如，使用

.caption

而不是

#caption

答案 2 :(得分：0)

您正在使用id进行dom点击。 ID是唯一的。更好地使用ClassName代替id .try querySelectorAll()和forEach()分配点击事件所有图片元素

// 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.querySelectorAll('.myImg');
var modalImg = document.getElementById("img01");
var captionText = document.getElementById("caption");

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

// Get the <span> element that closes the modal
var span = document.getElementById('close');

// When the user clicks on <span> (x), close the modal
function close() {
  modal.style.display = "none";
}
span.addEventListener("click", close);
img.forEach(a=> a.addEventListener("click", openModal));
#myImg {
  border-radius: 5px;
  cursor: pointer;
  transition: 0.3s;
}

#myImg:hover {
  opacity: 0.7;
}

.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)
  }
}

.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;
}

@media only screen and (max-width: 700px) {
  .modal-content {
    width: 100%;
  }
}
<img id="myImg" class="myImg"src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">
<img id="myImg" class="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200">

<!-- The Modal -->
<div id="myModal" class="modal">
  <span class="close" id="close">&times;</span>
  <img class="modal-content" id="img01">
  <div id="caption"></div>
</div>

答案 3 :(得分：0)

使用类而不是id。 或者，您也可以通过内联添加事件。

//and your function will looks like:
 function openModal(element){
    modal.style.display = "block";
    modalImg.src = element.src;
    captionText.innerHTML = element.alt;
}
// and remove img.addEventListener("click", openModal);
<img id="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200" onclick="openModal(this)">
<img id="myImg" src="img_fjords.jpg" alt="Trolltunga, Norway" width="300" height="200" onclick="openModal(this)">

答案 4 :(得分：0)

尝试一下 

// Get the Modal and modal-img
let modal = document.querySelector("#myModal");
let modalImg = document.querySelector(".modal-img");

// Show Modal
function showModal(elem) {
  modal.classList.remove("hide");
  modalImg.setAttribute("src", elem.src);
}

// Hide Modal
function hideModal() {
  modal.classList.add("hide");
}

// Hide Modal when backdrop (black transparent area) is clicked
modal.onclick = function (event) {
  if(event.target === modal) {
    hideModal();
  }
}
* {
  box-sizing: border-box;
  font-family: sans-serif;
}

/* Style Modal Container */
.modal {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: -webkit-flex;
  -webkit-align-items: center;
  -webkit-justify-content: center;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(0, 0, 0, .6);
  overflow: auto;
}

.hide {
  display: none;
}

/* Style Modal Content */
.modal-content {
  width: 75%;
  height: 75%;
  -webkit-animation: .4s slide;
  animation: .4s slide;
}

/* Adding Animation */
@-webkit-keyframes slide {
  from {
    opacity: 0;
    -webkit-transform: translateY(-50px);
    transform: translateY(-50px);
  }
  to {
    opacity: 1;
    -webkit-transform: translateY(0);
    transform: translateY(0);
  }
}

@keyframes slide {
  from {
    opacity: 0;
    -webkit-transform: translateY(-50px);
    transform: translateY(-50px);
  }
  to {
    opacity: 1;
    -webkit-transform: translateY(0);
    transform: translateY(0);
  }
}

/* Style Modal Header */
.modal-header {
  display: -webkit-flex;
  -webkit-align-items: flex-start;
  -webkit-justify-content: space-between;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 1rem 1rem;
  background-color: white;
}

/* Style Close Button */
.close {
  padding: 1rem 1rem;
  margin: -1rem -1rem -1rem auto;
  background-color: transparent;
  border: none;
  float: right;
  font-size: 1.5rem;
  font-weight: 700;
  color: #000;
  opacity: .5;
  cursor: pointer;
}

/* Style Modal Body */
.modal-body {
  position: relative;
  -webkit-flex: 1 1 auto;
  flex: 1 1 auto;
}

/* Style Modal Image */
.modal-img {
  width: 100%;
  height: auto;
  object-fit: cover;
}
<p>Click the Images below:</p>

<!-- Image trigger Modal -->
<img onclick="showModal(this)" src="https://parrot-tutorial.com/images/carousel_red3.jpg" style="width: 300px;">
<img onclick="showModal(this)" src="https://parrot-tutorial.com/images/air_ballon.jpg" style="width: 300px;">
<img onclick="showModal(this)" src="https://parrot-tutorial.com/images/nature_autumn.jpg" style="width: 300px;">

<!-- *************** Modal *************** -->
<div class="modal hide" id="myModal" tabindex="-1">
  <div class="modal-content">

    <!-- Modal Header -->
    <div class="modal-header">
      <button type="button" class="close" onclick="hideModal()">&times;</button>
    </div>

    <!-- Modal Body -->
    <div class="modal-body">
      <img class="modal-img" src="/images/carousel_3.jpg">
    </div>

  </div>
</div>

参考： How To Create Modal Images

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