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本章代码结构: 主入口Test.tsx , 组件:ResizeControl.tsx
本章花费俩天时间完成代码例子, 单独抽离代码 封装好一个 ResizeControl 组件, 拿来即用。
代码中
const domObj = document.getElementById(
resize-item-${startPos.id})
这句是关键代码, 不然获取的dom节点有问题,导致多个红色div操作时候会重叠
- ResizeControl.tsx
/* eslint-disable no-case-declarations */
import { FC, useEffect, useRef, useState } from 'react';
import styles from './index.module.scss';
import type { Demo } from '../../pages/Test';interface PropsType {children: JSX.Element | JSX.Element[];value: Demo;emitData: (val: Demo) => void;
}// 获取旋转角度参数
function getRotate(transform: string) {// 假设 transform 是 "rotate(45deg)"// console.info('transform', transform);if (!transform) return 0;const match = /rotate\(([^)]+)\)/.exec(transform);const rotate = match ? parseFloat(match[1]) : 0;// console.info(890, rotate);return rotate;
}const ResizeControl: FC<PropsType> = (props: PropsType) => {const { children, value, emitData } = props;const points = ['lt', 'tc', 'rt', 'rc', 'br', 'bc', 'bl', 'lc'];const [startPos, setStartPos] = useState<Demo>(value);const resizeItemRef = useRef(null);const isDown = useRef(false);const [direction, setDirection] = useState('');useEffect(() => {document.addEventListener('mouseup', handleMouseUp);document.addEventListener('mousemove', handleMouseMove);return () => {document.removeEventListener('mouseup', handleMouseUp);document.removeEventListener('mousemove', handleMouseMove);};}, [isDown, startPos]);// 鼠标被按下const onMouseDown = (e: React.MouseEvent<HTMLDivElement>) => {console.info('onMouseDown', e.currentTarget);e.stopPropagation();// e.preventDefault();// 获取 整个 resize-item 的dom节点const domObj = document.getElementById(`resize-item-${startPos.id}`);if (!domObj) return;resizeItemRef.current = domObj;if (!resizeItemRef.current) return;const { width, height, transform } = resizeItemRef.current.style;// 获取当前操作 dom data-keyconst direction = e.currentTarget.getAttribute('data-key') || '';console.log('元素方向', direction);setDirection(direction);// 获取旋转角度const rotate = getRotate(transform);// 记录状态isDown.current = true;setStartPos({...startPos,startX: e.clientX,startY: e.clientY,width: +width.replace(/px/, '') - 2,height: +height.replace(/px/, '') - 2,rotate,});};const handleMouseMove = (e: { clientX: number; clientY: number }) => {if (isDown.current && resizeItemRef.current) {const { rotate, startX, startY } = startPos;let { height, width, left, top } = startPos;// console.log('startPos', startPos);const curX = e.clientX;const curY = e.clientY;// 计算偏移量const offsetX = curX - startX;const offsetY = curY - startY;// console.info('offsetX', offsetX, offsetY);const rect = resizeItemRef.current.getBoundingClientRect();let nowRotate = 0;switch (direction) {// 右中case 'rc':width += offsetX;break;// 左中case 'lc':width -= offsetX;left += offsetX;break;// 底中case 'bc':height += offsetY;break;// 顶中case 'tc':height -= offsetY;top += offsetY;break;// 右上角case 'rt':height -= offsetY;top += offsetY;width += offsetX;break;// 左上角case 'lt':height -= offsetY;top += offsetY;width -= offsetX;left += offsetX;break;// 右下角case 'br':height += offsetY;width += offsetX;break;// 左下角case 'bl':height += offsetY;width -= offsetX;left += offsetX;break;case 'rotate':// 获取元素中心点位置const centerX = rect.left + rect.width / 2;const centerY = rect.top + rect.height / 2;// 旋转前的角度const rotateDegreeBefore =Math.atan2(startY - centerY, startX - centerX) / (Math.PI / 180);// 旋转后的角度const rotateDegreeAfter =Math.atan2(curY - centerY, curX - centerX) / (Math.PI / 180);// 获取旋转的角度值nowRotate = rotateDegreeAfter - rotateDegreeBefore + rotate;resizeItemRef.current.style.transform = `rotate(${nowRotate}deg)`;break;case 'move':left += offsetX;top += offsetY;// 获取父元素的边界 (打开注释, 可验证边界条件判断)// const parent = resizeItemRef.current.parentElement;// if (!parent) return;// const parentRect = parent.getBoundingClientRect();// // 限制div不超过父元素的边界// const maxTop = parentRect.height - height;// const maxLeft = parentRect.width - width;// left = Math.min(Math.max(left, 0), maxLeft);// top = Math.min(Math.max(top, 0), maxTop);break;}// console.log('-----', width, height);resizeItemRef.current.style.width = width + 'px';resizeItemRef.current.style.height = height + 'px';resizeItemRef.current.style.left = left + 'px';resizeItemRef.current.style.top = top + 'px';const newPos = {...startPos,height,width,startX: curX, startY: curY,left,top,rotate: nowRotate,};emitData(newPos);setStartPos(newPos);}};if (!children) return null;const handleMouseUp = () => {console.info('clear。。。。');isDown.current = false;resizeItemRef.current = null;};return (<divclassName={styles['resize-item']}style={{left: `${startPos.left}px`,top: `${startPos.top}px`,width: `${startPos.width + 2}px`,height: `${startPos.height + 2}px`,}}id={`resize-item-${startPos.id}`}>{points.map((item, index) => (<divkey={index}data-key={item}onMouseDown={onMouseDown}className={[styles['resize-control-btn'],styles[`resize-control-${item}`],].join(' ')}></div>))}<divclassName={styles['resize-control-rotator']}onMouseDown={onMouseDown}data-key={'rotate'}>转</div><divdata-key={'move'}onMouseDown={(e) => onMouseDown(e)}style={{ width: '100%', height: '100%', background: 'yellow' }}>{/* <span style={{ wordBreak: 'break-all', fontSize: '10px' }}>{JSON.stringify(startPos)}</span> */}{children}</div></div>);
};
export default ResizeControl;
- ResizeControl/index.module.scss
.resize-item {cursor: move;position: absolute;z-index: 2;border: 1px dashed yellow;box-sizing: border-box;
}$width_height: 4px; // 建议偶数.resize-control-btn {position: absolute;width: $width_height;height: $width_height;background: yellow;// user-select: none; // 注意禁止鼠标选中控制点元素,不然拖拽事件可能会因此被中断z-index: 1;
}.resize-control-btn.resize-control-lt {cursor: nw-resize;top: $width_height / -2;left: $width_height / -2;
}
.resize-control-btn.resize-control-tc {cursor: ns-resize;top: $width_height / -2;left: 50%;margin-left: $width_height / -2;
}
.resize-control-btn.resize-control-rt {cursor: ne-resize;top: $width_height / -2;right: $width_height / -2;
}
.resize-control-btn.resize-control-rc {cursor: ew-resize;top: 50%;margin-top: $width_height / -2;right: $width_height / -2;
}
.resize-control-btn.resize-control-br {cursor: se-resize;bottom: $width_height / -2;right: $width_height / -2;
}
.resize-control-btn.resize-control-bc {cursor: ns-resize;bottom: $width_height / -2;left: 50%;margin-left: $width_height / -2;
}
.resize-control-btn.resize-control-bl {cursor: sw-resize;bottom: $width_height / -2;left: $width_height / -2;
}
.resize-control-btn.resize-control-lc {cursor: ew-resize;top: 50%;margin-top: $width_height / -2;left: $width_height / -2;
}.resize-control-rotator {position: absolute;cursor: pointer;bottom: -20px;left: 50%;margin-left: -10px;width: 20px;text-align: center;font-size: 10px;background: red;
}
- 主入口 Test.tsx
import React, { useState, DragEvent, useRef, useEffect } from 'react';
import ResizeControl from '../../components/ResizeControl';export interface Demo {id: number;left: number;top: number;startX: number;startY: number;width: number;height: number;rotate: number;
}// 获取元素旋转角度
function getDomRotate(transform: string) {// 假设 transform 是 "rotate(45deg)"// console.info('transform', transform);const match = /rotate\(([^)]+)\)/.exec(transform);const rotate = match ? parseFloat(match[1]) : 0;// console.info(890, rotate);return rotate;
}const App: React.FC = () => {const [demos, setDemos] = useState<Demo[]>([]);const divRef = useRef<HTMLDivElement | null>(null);const [activeDomId, setActiveDomId] = useState(0);const handleDragStart = (e: DragEvent<HTMLDivElement>, id: number) => {e.dataTransfer.setData('id', id.toString());// 鼠标偏移量const offsetX = e.clientX - e.currentTarget.getBoundingClientRect().left;const offsetY = e.clientY - e.currentTarget.getBoundingClientRect().top;e.dataTransfer.setData('offsetX', offsetX.toString());e.dataTransfer.setData('offsetY', offsetY.toString());divRef.current = e.currentTarget;};const handleDrop = (e: DragEvent<HTMLDivElement>) => {e.preventDefault();console.info('鼠标释放位置', e.clientX, e.clientY);const contentDom = document.getElementById('content');if (!contentDom) return;const contentStyle = contentDom.getBoundingClientRect();// console.info('contentStyle', contentStyle);const { left, top } = contentStyle;const offsetX = +e.dataTransfer.getData('offsetX') || 0;const offsetY = +e.dataTransfer.getData('offsetY') || 0;// console.info('offsetX', offsetX, offsetY);const newLeft = e.clientX - left - offsetX;const newTop = e.clientY - top - offsetY;if (!divRef.current) return;const { width, height, transform } = divRef.current.style;// 元素旋转角度let rotate = 0;if (!transform) {rotate = 0;} else {rotate = getDomRotate(transform);}const newDemo: Demo = {id: e.dataTransfer.getData('id'),startX: e.clientX,startY: e.clientY,left: newLeft,top: newTop,width: +width.replace(/px/, ''),height: +height.replace(/px/, ''),rotate,};setDemos([...demos, newDemo]);};const handleDragOver = (e: DragEvent<HTMLDivElement>) => {e.preventDefault();};return (<div><divid="demo"draggableonDragStart={(e) => handleDragStart(e, +new Date())}style={{width: '100px',height: '100px',backgroundColor: 'red',margin: '30px',cursor: 'pointer',}}>demo2</div><divid="content"onDrop={handleDrop}onDragOver={handleDragOver}style={{width: '300px',height: '300px',margin: '30px',backgroundColor: 'blue',position: 'relative',}}>{demos.map((demo) => (<ResizeControlkey={demo.id}value={demo}emitData={(data) => {setDemos((prevDemos) =>prevDemos.map((a) => {return a.id == data.id ? data : a;}));}}>{/* 当前 div 组件 */}<divstyle={{backgroundColor: 'red',width: '100%',height: '100%',}}>{/* <span style={{ wordBreak: 'break-all', fontSize: '10px' }}>{JSON.stringify(demo)}</span> */}</div></ResizeControl>))}</div></div>);
};export default App;
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