JS：day07

一、className属性

给元素添加一个新的class属性，

    var test=document.getElementById("test");
    test.onclick=function(){
        console.log(1);
        /*给当前元素增加一个class属性*/
        addClass(this,"click")
    };
    function addClass(element,value){
        if(!element.className){
            element.className = value;
        }else{
            var newClassName = element.className;
            newClassName += " ";
            newClassName += value ;
            element.className = newClassName;
        }
    }

二、HTML5 创建画布

function draw(){
        var canvas = document.getElementById("draw-in-me");
        if(canvas.getContext){
            var ctx = canvas.getContext("2d");
            ctx.beginPath();
            ctx.moveTo(120.0,32.0);
            ctx.bezierCurveTo(120.0,36.4,116.4,40.0,112.0,40.0);
            ctx.lineTo(8.0,40.0);
            ctx.bezierCurveTo(3.6,40.0,0.0,36.4,0.0,32.0);
            ctx.lineTo(0.0,8.0);
            ctx.bezierCurveTo(0.0,3.6,3.6,0.0,8.0,0.0);
            ctx.lineTo(112.0,0.0);
            ctx.bezierCurveTo(116.4,0.0,120.0,3.6,120.0,8.0);
            ctx.lineTo(120.0,32.0);
            ctx.closePath();
            ctx.fill();
            ctx.lineWidth = 2.0;
            ctx.strokeStyle = "rgb(255,255,255)";
            ctx.stroke();
        }
    }
    draw();