邢台信息港人力资源如何优化标题关键词
文章目录
- 1. 为什么鼠标单击的时候触发了`mousemove`事件？明明鼠标没有移动
- 2. 鼠标拖拽元素怎么能不触发单击事件？怎么处理鼠标在元素内的相对定位，而不是每次定位到左上角？
- 方式一：拖拽的元素没有注册click监听就不会触发单击事件绑定的函数
- 方式二：通过鼠标是否发生移动判断当前元素是需要移动还是需要单击
- 方式三：考虑鼠标在元素内相对定位问题，鼠标点击位置就是拖拽位置
- 3. 鼠标拖拽元素怎么能不触发选中文本？
- 方式一：鼠标按下时，阻止默认事件`e.preventDefault()`，不触发选中文本
- 方式二：鼠标按下时，修改当前元素style样式，鼠标抬起再取消
- 参考链接
鼠标拖拽需要注意什么问题？
鼠标拖拽会依次触发mousedown mousemove mouseup click事件。很多时候在一个元素既需要拖拽，又需要单击的时候，应该怎么避免在拖拽时不触发单击事件？不触发文本选中问题？
1. 为什么鼠标单击的时候触发了mousemove事件？明明鼠标没有移动
？
2. 鼠标拖拽元素怎么能不触发单击事件？怎么处理鼠标在元素内的相对定位，而不是每次定位到左上角？
方式一：拖拽的元素没有注册click监听就不会触发单击事件绑定的函数
- 示例代码
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>测试拖拽</title><style>body{background-color: #f5f5f5;}#triggerDiv {position: fixed;left: 0px;top: 0px;width: 100px;height: 100px;background-color: red;position: absolute;text-align: center;line-height: 100px;vertical-align: middle;cursor: pointer;border-radius: 50%;}</style>
</head>
<body><div id="triggerDiv">拖拽</div>
</body><script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {isMouseDown = trueconsole.log('mousedown:', isMouseDown)})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove:', isMouseDown)if (isMouseDown) {triggerELe.style.left = e.clientX + 'px'triggerELe.style.top = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {isMouseDown = falseconsole.log('mouseup:', isMouseDown)})// 鼠标离开：事件顺序 mouseout > mouseleave// triggerELe.addEventListener('mouseout', function(e) {// isMouseDown = false// console.log('mouseout:', isMouseDown)// })// triggerELe.addEventListener('mouseleave', function(e) {// isMouseDown = false// console.log('mouseleave:', isMouseDown)// })// 给元素绑定了单击事件// triggerELe.addEventListener('click', function(e) {// console.log('click')// })
</script>
</html>
- 通过对比是否绑定单击事件，判断单击是否被触发
方式二：通过鼠标是否发生移动判断当前元素是需要移动还是需要单击
- 如果
mousemove事件没有被触发，那mouseup发生时当前元素应该执行单击事件- 示例代码
<script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false // 鼠标是否按下let isMouseMove = false // 鼠标是否发生移动// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {console.log('mousedown')isMouseDown = trueisMouseMove = false})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove')isMouseMove = trueif (isMouseDown) {triggerELe.style.left = e.clientX + 'px'triggerELe.style.top = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {console.log('mouseup')isMouseDown = falseif (isMouseMove) {console.log('鼠标移动了')} else {console.log('鼠标没有移动，执行单击事件')}})
</script>
- 通过判断是否触发
mousemove事件，决定是否执行单击事件
- 如果
mousedown和mouseup事件发生后，鼠标位置没有改变应该执行单击事件- 示例代码
<script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false // 鼠标是否按下// ========= 鼠标移动相关变量 ===========let beforeX = 0 // 鼠标按下时的x坐标let beforeY = 0 // 鼠标按下时的y坐标let afterX = 0 // 鼠标抬起时的x坐标let afterY = 0 // 鼠标抬起时的y坐标// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {console.log('mousedown')isMouseDown = truebeforeX = e.offsetXbeforeY = e.offsetY})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove')if (isMouseDown) {triggerELe.style.left = e.clientX + 'px'triggerELe.style.top = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {console.log('mouseup')isMouseDown = falseafterX = e.offsetXafterY = e.offsetYconsole.log('beforeX:', beforeX, 'beforeY:', beforeY, 'afterX:', afterX, 'afterY:', afterY)// 前后坐标相等，说明没有移动，执行单击事件if (beforeX !== afterX || beforeY !== afterY) {console.log('鼠标移动了')} else {console.log('鼠标没有移动，执行单击事件')}})// // 给元素绑定了单击事件// triggerELe.addEventListener('click', function(e) {// console.log('click')// })
</script>
- 思路：如果鼠标前后坐标没有发生变化执行单击事件
注！由于页面缩放问题，可能会出现鼠标没有移动但是前后坐标不一致的问题。
方式三：考虑鼠标在元素内相对定位问题，鼠标点击位置就是拖拽位置
<script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false // 鼠标是否按下// ========= 鼠标移动相关变量 ===========let beforeX = 0 // 鼠标按下时的x坐标let beforeY = 0 // 鼠标按下时的y坐标let afterX = 0 // 鼠标抬起时的x坐标let afterY = 0 // 鼠标抬起时的y坐标let initX = 0 // 鼠标按下时的x坐标let initY = 0 // 鼠标按下时的y坐标// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {console.log('mousedown')isMouseDown = truebeforeX = e.offsetXbeforeY = e.offsetY// 鼠标按下时的坐标initX = e.offsetXinitY = e.offsetY})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove')if (isMouseDown) {triggerELe.style.left = (e.clientX - initX) + 'px'triggerELe.style.top = (e.clientY - initY) + 'px'// 鼠标移动时的坐标afterX = e.offsetX + 'px'afterY = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {console.log('mouseup')isMouseDown = falseafterX = e.offsetXafterY = e.offsetYconsole.log('beforeX:', beforeX, 'beforeY:', beforeY, 'afterX:', afterX, 'afterY:', afterY)// 前后坐标相等，说明没有移动，执行单击事件if (beforeX !== afterX || beforeY !== afterY) {console.log('鼠标移动了')} else {console.log('鼠标没有移动，执行单击事件')}})// // 给元素绑定了单击事件// triggerELe.addEventListener('click', function(e) {// console.log('click')// })
</script>
3. 鼠标拖拽元素怎么能不触发选中文本？
方式一：鼠标按下时，阻止默认事件e.preventDefault()，不触发选中文本
<script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false // 鼠标是否按下// ========= 鼠标移动相关变量 ===========let beforeX = 0 // 鼠标按下时的x坐标let beforeY = 0 // 鼠标按下时的y坐标let afterX = 0 // 鼠标抬起时的x坐标let afterY = 0 // 鼠标抬起时的y坐标let initX = 0 // 鼠标按下时的x坐标let initY = 0 // 鼠标按下时的y坐标// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {console.log('mousedown')isMouseDown = truebeforeX = e.offsetXbeforeY = e.offsetY// 鼠标按下时的坐标initX = e.offsetXinitY = e.offsetY// 阻止默认事件e.preventDefault()})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove')if (isMouseDown) {triggerELe.style.left = (e.clientX - initX) + 'px'triggerELe.style.top = (e.clientY - initY) + 'px'// 鼠标移动时的坐标afterX = e.offsetX + 'px'afterY = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {console.log('mouseup')isMouseDown = falseafterX = e.offsetXafterY = e.offsetYconsole.log('beforeX:', beforeX, 'beforeY:', beforeY, 'afterX:', afterX, 'afterY:', afterY)// 前后坐标相等，说明没有移动，执行单击事件if (beforeX !== afterX || beforeY !== afterY) {console.log('鼠标移动了')} else {console.log('鼠标没有移动，执行单击事件')}})// // 给元素绑定了单击事件// triggerELe.addEventListener('click', function(e) {// console.log('click')// })
</script>
方式二：鼠标按下时，修改当前元素style样式，鼠标抬起再取消
<script>let triggerELe = document.getElementById('triggerDiv')let isMouseDown = false // 鼠标是否按下// ========= 鼠标移动相关变量 ===========let beforeX = 0 // 鼠标按下时的x坐标let beforeY = 0 // 鼠标按下时的y坐标let afterX = 0 // 鼠标抬起时的x坐标let afterY = 0 // 鼠标抬起时的y坐标let initX = 0 // 鼠标按下时的x坐标let initY = 0 // 鼠标按下时的y坐标// 鼠标按下triggerELe.addEventListener('mousedown', function(e) {console.log('mousedown')isMouseDown = truebeforeX = e.offsetXbeforeY = e.offsetY// 鼠标按下时的坐标initX = e.offsetXinitY = e.offsetY// 不选中文字triggerELe.style.userSelect = 'none'// 添加css// css// .no-select {// user-select: none// }})// 鼠标移动triggerELe.addEventListener('mousemove', function(e) {console.log('mousemove')if (isMouseDown) {triggerELe.style.left = (e.clientX - initX) + 'px'triggerELe.style.top = (e.clientY - initY) + 'px'// 鼠标移动时的坐标afterX = e.offsetX + 'px'afterY = e.clientY + 'px'}})// 鼠标抬起triggerELe.addEventListener('mouseup', function(e) {console.log('mouseup')isMouseDown = falseafterX = e.offsetXafterY = e.offsetYconsole.log('beforeX:', beforeX, 'beforeY:', beforeY, 'afterX:', afterX, 'afterY:', afterY)// 前后坐标相等，说明没有移动，执行单击事件if (beforeX !== afterX || beforeY !== afterY) {console.log('鼠标移动了')// 移除css// .no-select {// user-select: text// }triggerELe.style.userSelect = 'text'} else {console.log('鼠标没有移动，执行单击事件')}})// // 给元素绑定了单击事件// triggerELe.addEventListener('click', function(e) {// console.log('click')// })
</script>
参考链接
可拖动DIV层的实现方法_可拖动的div-CSDN博客
Javascript设置拖拽时不触发点击事件_鼠标拖动列表,会触发列表项的点击事件,如何阻止-CSDN博客