js实现响应按钮点击弹出可拖拽的非模态对话框完整实例【测试可用】[原创]

来源：jb51　　时间：2023/4/24 8:50:08　　对本文有异议

1.css部分：

.dialog {
? display: none;
? position: absolute;
? left: 50%;
? top: 50%;
? transform: translate(-50%, -50%);
? background-color: #fff;
? border-radius: 5px;
? box-shadow: 0 10px 20px rgba(0, 0, 0, .3);
? z-index: 9999;
}
 
.dialog-header {
? background-color: #f6f7f8;
? padding: 10px;
? border-top-left-radius: 5px;
? border-top-right-radius: 5px;
? cursor: move;
}
 
.dlgtitle {
? font-weight: bold;
? font-size: 16px;
}
 
.close-btn {
? float: right;
? cursor: pointer;
}
 
.dialog-content {
? padding: 20px;
}

2.html部分：

<button id="openBtn">打开对话框</button>
 
<div id="dialog" class="dialog">
? <div class="dialog-header">
? ? <span class="dlgtitle">对话框标题</span>
? ? <span class="close-btn">&times;</span>
? </div>
? <div class="dialog-content">
? ? <p>这里是对话框内容</p>
? </div>
</div>

3.JavaScript部分：

var dialog = document.getElementById('dialog');
var openBtn = document.getElementById('openBtn');
var closeBtn = document.querySelector('.close-btn');
var isDragging = false;
var mouseX, mouseY, dialogLeft, dialogTop;
 
// 鼠标按下时记录鼠标位置以及对话框位置
dialogHeaderMouseDown = function(e) {
? isDragging = true;
? mouseX = e.clientX;
? mouseY = e.clientY;
? dialogLeft = dialog.offsetLeft;
? dialogTop = dialog.offsetTop;
}
 
// 鼠标移动时移动对话框
// document.onmousemove = function(e) {
dialogHeaderMouseMove = function(e) {
? if (isDragging) {
? ? var moveX = e.clientX - mouseX;
? ? var moveY = e.clientY - mouseY;
? ? dialog.style.left = dialogLeft + moveX + 'px';
? ? dialog.style.top = dialogTop + moveY + 'px';
? }
}
 
// 鼠标松开时停止拖动
// document.onmouseup = function() {
dialogHeaderMouseup = function() {
? isDragging = false;
}
 
// 点击打开按钮显示对话框
openBtn.onclick = function() {
? dialog.style.display = 'block';
}
 
// 点击关闭按钮或对话框外部关闭对话框
closeBtn.onclick = function() {
? dialog.style.display = 'none';
}
 
dialog.onclick = function(e) {
? if (e.target == dialog) {
? ? dialog.style.display = 'none';
? }
}
 
// 鼠标按下对话框头部，开始拖动对话框
var header = document.querySelector('.dialog-header');
header.addEventListener('mousedown', dialogHeaderMouseDown);
header.addEventListener('mousemove', dialogHeaderMouseMove);
header.addEventListener('mouseup', dialogHeaderMouseup);

可以使用jb51在线工具：http://tools.jb51.net/code/WebCodeRun 测试上述代码运行效果。

附：完整示例代码：

<!DOCTYPE html>
<html lang="zh_CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>可拖拽非模态对话框</title>
<style>
.dialog {
  display: none;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  background-color: #fff;
  border-radius: 5px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, .3);
  z-index: 9999;
}
 
.dialog-header {
  background-color: #f6f7f8;
  padding: 10px;
  border-top-left-radius: 5px;
  border-top-right-radius: 5px;
  cursor: move;
}
 
.dlgtitle {
  font-weight: bold;
  font-size: 16px;
}
 
.close-btn {
  float: right;
  cursor: pointer;
}
 
.dialog-content {
  padding: 20px;
}
</style>
</head>
<body>
<button id="openBtn">打开对话框</button>
<div id="dialog" class="dialog">
  <div class="dialog-header">
    <span class="dlgtitle">对话框标题</span>
    <span class="close-btn">&times;</span>
  </div>
  <div class="dialog-content">
    <p>这里是对话框内容</p>
  </div>
</div>
<script>
var dialog = document.getElementById('dialog');
var openBtn = document.getElementById('openBtn');
var closeBtn = document.querySelector('.close-btn');
var isDragging = false;
var mouseX, mouseY, dialogLeft, dialogTop;
 
// 鼠标按下时记录鼠标位置以及对话框位置
dialogHeaderMouseDown = function(e) {
  isDragging = true;
  mouseX = e.clientX;
  mouseY = e.clientY;
  dialogLeft = dialog.offsetLeft;
  dialogTop = dialog.offsetTop;
}
 
// 鼠标移动时移动对话框
// document.onmousemove = function(e) {
dialogHeaderMouseMove = function(e) {
  if (isDragging) {
    var moveX = e.clientX - mouseX;
    var moveY = e.clientY - mouseY;
    dialog.style.left = dialogLeft + moveX + 'px';
    dialog.style.top = dialogTop + moveY + 'px';
  }
}
 
// 鼠标松开时停止拖动
// document.onmouseup = function() {
dialogHeaderMouseup = function() {
  isDragging = false;
}
 
// 点击打开按钮显示对话框
openBtn.onclick = function() {
  dialog.style.display = 'block';
}
 
// 点击关闭按钮或对话框外部关闭对话框
closeBtn.onclick = function() {
  dialog.style.display = 'none';
}
 
dialog.onclick = function(e) {
  if (e.target == dialog) {
    dialog.style.display = 'none';
  }
}
 
// 鼠标按下对话框头部，开始拖动对话框
var header = document.querySelector('.dialog-header');
header.addEventListener('mousedown', dialogHeaderMouseDown);
header.addEventListener('mousemove', dialogHeaderMouseMove);
header.addEventListener('mouseup', dialogHeaderMouseup);
</script>
</body>
</html>