碰撞菜单（碰撞弹框的效果） 

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <style>
            #div1{
                width: 100px;
                height: 100px;
                background: red;
                position: absolute;
            }
            
        </style>
        <script>
            window.onload=function(){
                var oDiv=document.getElementById("div1");
                var disX=0;
                var disY=0;
                
                var prevX=0;
                var prevY=0;
                var iSpeedX=0;
                var iSpeedY=0;
                var timer=null;
                
                
                oDiv.onmousedown=function(ev){
                    var ev=ev||window.event;
                    disX=ev.clientX-oDiv.offsetLeft;
                    disY=ev.clientY-oDiv.offsetTop;
                    prevX=ev.clientX;
                    prevY=ev.clientY;
                document.onmousemove=function(ev){
                    var ev=ev||window.event;
                    oDiv.style.left=ev.clientX-disX+"px";
                    oDiv.style.top=ev.clientY-disY+"px";
                    
                    iSpeedX=ev.clientX-prevX;
                    iSpeedY=ev.clientY-prevY;
                    
                    prevX=ev.clientX;
                    prevY=ev.clientY;
                }
                document.onmouseup=function(){
                    document.onmousemove=null;
                    document.onmouseup=null;
                    
                    startMove();
                }
                return false;
                };
                function startMove(){
                    clearInterval(timer);
                    timer=setInterval(function(){
                        iSpeedY+=3;
                        var L=oDiv.offsetLeft+iSpeedX;
                        var T=oDiv.offsetTop+iSpeedY;
                        if(T>document.documentElement.clientHeight-oDiv.offsetHeight){
                            T=document.documentElement.clientHeight-oDiv.offsetHeight;
                            iSpeedY*=-1;
                            iSpeedY*=0.75;
                            iSpeedX*=0.75;
                        }else if(T<0){
                            T=0;
                            iSpeedY*=-1;
                            iSpeedY*=0.75;
                        }
                        if(L>document.documentElement.clientWidth-oDiv.offsetWidth){
                            L=document.documentElement.clientWidth-oDiv.offsetWidth;
                            iSpeedX*=-1;
                            iSpeedX*=0.75;
                        }else if(L<0){
                            L=0;
                            iSpeedX*=-1;
                            iSpeedX*=0.75;
                        }
                        oDiv.style.left=L+"px";
                        oDiv.style.top=T+"px";
                    },30)
                }
            }
        </script>
    </head>
    <body>
        <div id="div1"></div>
    </body>
</html>

 

posted @ 2019-01-09 17:33  webxy  阅读(178)  评论(0)    收藏  举报