html5使用canvas畫空心圓與實(shí)心圓

    <canvas id="canvas" width="500" height="500"></canvas>
    代碼如下:
    var canvas=document.getElementById("canvas");
    var cxt=canvas.getContext("2d");
    //畫一個(gè)空心圓
    cxt.beginPath();
    cxt.arc(200,200,50,0,360,false);
    cxt.lineWidth=5;
    cxt.strokeStyle="green";
    cxt.stroke();//畫空心圓
    cxt.closePath();
    //畫一個(gè)實(shí)心圓
    cxt.beginPath();
    cxt.arc(200,100,50,0,360,false);
    cxt.fillStyle="red";//填充顏色,默認(rèn)是黑色
    cxt.fill();//畫實(shí)心圓
    cxt.closePath();
    //空心和實(shí)心的組合
    cxt.beginPath();
    cxt.arc(300,300,50,0,360,false);
    cxt.fillStyle="red";
    cxt.fill();
    cxt.strokeStyle="green";
    cxt.stroke();
    cxt.closePath();