js小球区域运动 js实现小球在页面规定的区域运动
Lv_SFeng 人气:0小球在页面规定的区域运动,碰到边界就改变运动方向。
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>小球运动</title> <style type="text/css"> #box { width: 600px; height: 300px; border: 1px solid red; position: relative; } #ball { width: 50px; height: 50px; border-radius: 25px; background-color: yellow; position: absolute; top: 0; left: 0; } button { position: relative; } </style> </head> <body> <div id="box"> <div id="ball"> </div> </div> <button id="stop" onclick="fly()">开始</button> <button id="stop" onclick="stop()">停止</button> <script type="text/javascript"> var ball = document.getElementById("ball"); //console.log(ball.offsetLeft); var sport; function fly() { var speedx = 1; var speedy = 1; sport = setInterval(function () { ball.style.left = ball.offsetLeft + speedx + 'px'; ball.style.top = ball.offsetTop + speedy + 'px'; if (ball.offsetTop >= 300 -50 || ball.offsetTop <= 0) { speedy *= -1; } if (ball.offsetLeft >= 600 -50 || ball.offsetLeft <= 0) { speedx *= -1; } }, 10) } function stop() { clearInterval(sport); //停止小球的运动 } </script> </body> </html>
效果图:
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