JS完美运动框架

// for in 循环 ---json
function getStyle(obj, attr) {
	return obj.currentStyle?obj.currentStyle[attr]:window.getComputedStyle(obj, false)[attr];
}

function getByClassName(parent, name) {
	var aResult = [];
	var arr = parent.getElementsByTagName('*');
	for (var i=0,len=arr.length; i<len;i++) {
		if (arr[i].className===name) {
			aResult.push(arr[i]);
		}
	}
	return aResult;
}

function startMove(obj, json, fn) {
	clearInterval(obj.timer);
	obj.timer = setInterval(function () {
		var bStop = true;
		for(var attr in json) {
			var icur = 0;
			if (attr==='opacity') {
				icur = parseInt(parseFloat(getStyle(obj, attr))*100);
			} else {
				icur = parseInt(getStyle(obj, attr));
			}
			var speed = (json[attr] - icur)/8;
			speed = speed>0?Math.ceil(speed):Math.floor(speed);

			if (icur!==json[attr]) {
				bStop = false;
			}
			if (attr==='opacity') {
				obj.style.opacity = (icur + speed) /100;
				obj.style.filter = "alpha(opacity="+(icur+speed)+")";
			} else {
				obj.style[attr] = icur + speed + 'px';
			}
		}
		if (bStop) {
			clearInterval(obj.timer);
			if (fn) {
				fn();
			}
		}
	},30);
}

不是完美版，还有些待修改的地方