css3 javascript 实现菜单按钮特效

一个菜单按钮特效案例，简单的实现了动态效果。

代码效果预览地址：

http://code.w3ctech.com/detail/2504

<div class="bar" id="menubar">

  <div class="menu" id="menu0">

  </div>
  <div class="menu" id="menu1">

  </div>
  <div class="menu" id="menu2">

  </div>
</div>

.bar{
            width:40px;
            height:40px;
            border:1px solid #ccc;
            border-radius:50%;
            position:fixed;
            top:10px;
            right:25px;
            z-index:1000;
            cursor:pointer;
        }
        .menu{
            width:20px;
            height:2px;
            background-color:#ccc;
            position:absolute;
            transform:translate3d(-50%,-50%,0);
            left:50%;
            transition:all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) 0s
        }
        #menu0{
            top:30%;
        }
        #menu1{
            top:50%;
        }
        #menu2{
            top:70%;
        }

window.onload = function () {
            var menubar = document.getElementById("menubar");
            var menu0 = document.getElementById("menu0");
            var menu1 = document.getElementById("menu1");
            var menu2 = document.getElementById("menu2");
            var i = 0;
            menubar.onclick = function () {
                i++;
                if (i % 2 == 1) {
                    menu0.style.top = 50 + "%";
                    menu1.style.display = "none";
                    menu2.style.top = 50 + "%";
                    menu0.style.transform = "translate3d(-50%,-50%,0) rotate(135deg)";
                    menu2.style.transform = "translate3d(-50%,-50%,0) rotate(405deg)";
                }
                else {
                    menu0.style.transform = "translate3d(-50%,-50%,0) rotate(0deg)";
                    menu2.style.transform = "translate3d(-50%,-50%,0) rotate(0deg)";
                    menu0.style.top = 30 + "%";
                    menu2.style.top = 70 + "%";
                    menu1.style.display = "block";
                }
            }

        }