寫一個運動小框架

1、需要獲取元素對象

document.getElementById();

2、需要在函數裏面回去樣式值

function Css(obj,attr){
    	if(obj.currentStyle){
 		return obj.currentStyle[arr];
 	}else{
 		return getComputedStyle(obj,false)[arr];
 	}
  }

3、寫一個定時器函數

obj.iTmer = setInterval(fn,30);

4、運動函數

function fn(){
    var iTmer = null;
    iSpeed = parseInt(getCss(objDid,‘left‘))>end?-iSpeed:iSpeed;
    obj.iTmer = setInterval(fn,30);
    var dir = null;
    if(arr == ‘opacity‘){
     dir = Math.round(getCss(obj,arr)*100) + iSpeed;
        if ( dir > end && iSpeed > 0 || dir < end && iSpeed < 0) {
        dir = end;
        }
        obj.style[arr] = (dir + iSpeed) / 100;
        obj.style.filter = ‘alpha(opacity=‘+ (dir + iSpeed) +‘)‘;
    }else{
        dir = parseInt(getCss(obj,arr)) + iSpeed;
        if ( dir > end && iSpeed > 0 || dir < end && iSpeed < 0) {
            dir = end;
        }
        obj.style[arr] = dir + ‘px‘; 
    }
    if ( dir == end ) {
        clearInterval( obj.iTmer );
    }
}

javascript運動的小框架