ESC键无法删除模态javascript

Question

我正在尝试使用键盘 ESC 键来转义模态框（通过使用纯 JavaScript 将其删除），但看起来好像出了点问题。

代码来自 W3SCHOOL 示例： W3school 示例

这是当人们按下键盘 ESC 键时我试图添加的代码以进行转义：

  document.addEventListener('keyup', function(event) {
    if (event.keyCode === 27) {
      modal.classList.remove('modal');
    }
  });

片段：

  document.addEventListener('keyup', function(event) {
    if (event.keyCode === 27) {
      modal.classList.remove('modal');
    }
  });

// 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";
}

body {font-family: Arial, Helvetica, sans-serif;}

#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%;
    }
}

Answer 1

查看他们的示例，这是当您单击关闭按钮时他们正在使用的事件处理程序：

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

因此，在escape按键的情况下，它应该是：

document.addEventListener('keyup', function(event) {
  if (event.keyCode === 27) {
    modal.style.display = 'none';
  }
});

或者，如果您更喜欢使用该event.key属性：

document.addEventListener('keyup', function(event) {
  if (event.key === 'Escape') {
    modal.style.display = 'none';
  }
});

这是工作片段：

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

document.addEventListener('keyup', function(event) {
  if (event.keyCode === 27) {
    modal.style.display = 'none';
  }
});

document.addEventListener('keyup', function(event) {
  if (event.key === 'Escape') {
    modal.style.display = 'none';
  }
});

在实际应用中，您可能需要稍微重构代码以创建一个单独的关闭模态的函数，然后在事件处理程序中使用它：

function closeModal() {
    modal.style.display = 'none';
}

// When the user clicks on <span> (x), close the modal
span.onclick = function() { 
    closeModal();
}

document.addEventListener('keyup', function(event) {
  if (event.key === 'Escape') {
    closeModal();
  }
});