标签：const 缩放 top 拖拽 5px div event resize left
一、HTML代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<link rel="stylesheet" href="./index.css" />
</head>
<body>
<div class="box" id="drag">
<div class="resize-handle top-left"></div>
<div class="resize-handle top"></div>
<div class="resize-handle top-right"></div>
<div class="resize-handle right"></div>
<div class="resize-handle bottom-right"></div>
<div class="resize-handle bottom"></div>
<div class="resize-handle bottom-left"></div>
<div class="resize-handle left"></div>
</div>
</body>
<script src="./index.js"></script>
</html>
二、CSS代码
.box {
position: absolute;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
width: 200px;
height: 200px;
background-color: #f0f0f0;
cursor: move;
}
.resize-handle {
position: absolute;
width: 10px;
height: 10px;
background-color: #000;
}
.top-left {
top: -5px;
left: -5px;
cursor: nw-resize;
}
.top {
top: -5px;
left: calc(50% - 5px);
cursor: ns-resize;
}
.top-right {
top: -5px;
right: -5px;
cursor: ne-resize;
}
.right {
top: calc(50% - 5px);
right: -5px;
cursor: ew-resize;
}
.bottom-right {
bottom: -5px;
right: -5px;
cursor: se-resize;
}
.bottom {
bottom: -5px;
left: calc(50% - 5px);
cursor: ns-resize;
}
.bottom-left {
bottom: -5px;
left: -5px;
cursor: sw-resize;
}
.left {
top: calc(50% - 5px);
left: -5px;
cursor: ew-resize;
}
三、JS代码
const dragElement = document.getElementById("drag");
// 拖拽功能
dragElement.addEventListener("mousedown", startDrag);
function startDrag(event) {
event.preventDefault();
const currentHandle = event.target;
const isResizeHandle = currentHandle.className.includes("resize-handle");
if (isResizeHandle) return;
const startX = event.clientX;
const startY = event.clientY;
const startLeft = dragElement.offsetLeft;
const startTop = dragElement.offsetTop;
document.addEventListener("mousemove", drag);
document.addEventListener("mouseup", stopDrag);
function drag(event) {
const dx = event.clientX - startX;
const dy = event.clientY - startY;
const newLeft = startLeft + dx;
const newTop = startTop + dy;
dragElement.style.left = newLeft + "px";
dragElement.style.top = newTop + "px";
}
function stopDrag() {
document.removeEventListener("mousemove", drag);
document.removeEventListener("mouseup", stopDrag);
}
}
// 缩放功能
const resizeHandles = document.getElementsByClassName("resize-handle");
Array.from(resizeHandles).forEach((handle) => {
handle.addEventListener("mousedown", startResize);
});
function startResize(event) {
event.preventDefault();
const currentHandle = event.target;
const direction = currentHandle.className.split(" ")[1];
const startX = event.clientX;
const startY = event.clientY;
const startWidth = dragElement.offsetWidth;
const startHeight = dragElement.offsetHeight;
const startLeft = dragElement.offsetLeft;
const startTop = dragElement.offsetTop;
document.addEventListener("mousemove", resize);
document.addEventListener("mouseup", stopResize);
function resize(event) {
const dx = event.clientX - startX;
const dy = event.clientY - startY;
let width = startWidth,
height = startHeight,
left = startLeft,
top = startTop;
if (direction.includes("left")) {
width = startWidth - dx + "px";
left = startLeft + dx / 2 + "px";
}
if (direction.includes("right")) {
width = startWidth + dx + "px";
left = startLeft + dx / 2 + "px";
}
if (direction.includes("top")) {
height = startHeight - dy + "px";
top = startTop + dy / 2 + "px";
}
if (direction.includes("bottom")) {
height = startHeight + dy + "px";
top = startTop + dy / 2 + "px";
}
if (parseInt(width) <= 0 || parseInt(height) <= 0) return;
dragElement.style.width = width;
dragElement.style.height = height;
dragElement.style.left = left;
dragElement.style.top = top;
}
function stopResize() {
document.removeEventListener("mousemove", resize);
document.removeEventListener("mouseup", stopResize);
}
}
标签：const,
缩放,
top,
拖拽,
5px,
div,
event,
resize,
left
From： https://blog.51cto.com/u_15997490/8741541