1、平面转换-旋转
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<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>img {width: 200px;transition: all 2s;}/* 鼠标悬停到图片上面，添加旋转效果 */img:hover {/* 正数：顺时针旋转； 负数：逆时针旋转 */transform: rotate(360deg);transform: rotate(-360deg);}</style>
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<body><img src="../photo/1.jpg" alt="">
</body>
</html>2、平面旋转-改变转换原点
默认情况下，转换原点是盒子中心点
取值
- 方位名词（left、top、right、bottom、center）
- 像素单位数值
- 百分比
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<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>img {width: 200px;border: 1px solid #000;transition: all 1s;transform-origin: right bottom;}img:hover {transform: rotate(360deg);}</style>
</head>
<body><img src="../photo/1.jpg" alt="">
</body>
</html>3、案例 时钟
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<html lang="en"><head><meta charset="UTF-8" /><meta name="viewport" content="width=device-width, initial-scale=1.0" /><title>Document</title><style>.clock {width: 250px;height: 250px;border: 8px solid #000;border-radius: 50%;margin: 100px auto;position: relative;}.line {/* 1.定位 */position: absolute;width: 4px;height: 250px;background-color: #999;left: 50%;transform: translate(-50%);}/* 线2: 旋转, 每条线旋转角度不同, 单独选中不同的line, 写rotate代码 *//* 一圈是360度, 等分成 xx 份 */.line:nth-child(2) {transform: translate(-50%) rotate(30deg);}.line:nth-child(3) {transform: translate(-50%) rotate(60deg);}.line:nth-child(4) {transform: translate(-50%) rotate(90deg);}.line:nth-child(5) {transform: translate(-50%) rotate(120deg);}.line:nth-child(6) {transform: translate(-50%) rotate(150deg);}/* 第一根和第四跟宽度大一些 */.line:nth-child(1),.line:nth-child(4) {width: 5px;}/* 遮罩圆形 */.cover {position: absolute;left: 50%;top: 50%;transform: translate(-50%, -50%);width: 200px;height: 200px;background-color: #fff;border-radius: 50%;}/* 表针 *//* 并集选择器放在单独选择器的上面, 避免transform属性的层叠 */.hour,.minute,.second {position: absolute;left: 50%;/* 盒子底部在盒子中间 */bottom: 50%;}.hour {width: 6px;height: 50px;background-color: #333;margin-left: -3px;transform: rotate(15deg);transform-origin: center bottom;}.minute {width: 5px;height: 65px;background-color: #333;margin-left: -3px;transform: rotate(90deg);transform-origin: center bottom;}.second {width: 4px;height: 80px;background-color: red;margin-left: -2px;transform: rotate(240deg);transform-origin: center bottom;}/* 螺丝 */.dotted {position: absolute;left: 50%;top: 50%;transform: translate(-50%, -50%);width: 18px;height: 18px;background-color: #333;border-radius: 50%;}</style></head><body><div class="clock"><!-- 刻度线 --><div class="line"></div><div class="line"></div><div class="line"></div><div class="line"></div><div class="line"></div><div class="line"></div><!-- 遮罩圆形 --><div class="cover"></div><!-- 表针 --><div class="hour"></div><div class="minute"></div><div class="second"></div><!-- 螺丝 --><div class="dotted"></div></div></body>
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