// 封装获取计算后元素样式函数，返回小数 function getStyle(obj, name) { if (obj.currentStyle) { return obj.currentStyle[name]; } else { return getComputedStyle(obj, '') [name]; } } // 任意值运动框架 function startMove(obj, name, iTarget ) { clearInterval(obj.timer); obj.timer = setInterval(move, 30); function move() { var current = 0; if (name === 'opacity') { // 用 parseFloat 保留小数并去掉后面 px ，从左至右提取数字，遇到不是数字跳出 // Math.round() 四舍五入取整 current = Math.round(parseFloat(getStyle(obj, name))*100); } else { // 用 parseInt 去掉后面 px ，从左至右提取数字，遇到不是数字跳出 current = parseInt(getStyle(obj, name)); } var speed = (iTarget - current)/3; if (speed < 0) { speed = Math.floor(speed); } else { speed = Math.ceil(speed); } if (iTarget === current) { clearInterval(obj.timer); } else { if (name === 'opacity') { obj.style[name] = (current + speed)/100; obj.style.filter = "alpha("+[name]+ "=" + (current + speed) + ")"; } else { obj.style[name] = current + speed + 'px'; } } // console.log('iTarget',iTarget,'current',current,'getStyle',getStyle(obj, name),speed) } }