2016-11-12 62 views

回答

1

试试这个:

<script> 
    var canvas = document.getElementById('myCanvas'), 
     context = canvas.getContext('2d'), 
     startAngle = 1.2 * Math.PI, 
     endAngle = 0.8 * Math.PI; 

    context.beginPath(); 
    context.moveTo(50, 70); 
    context.lineTo(250, 70); 
    context.arc(300, 100, 50, startAngle, endAngle, false); 
    context.lineTo(50, 130); 
    context.closePath(); 
    context.lineWidth = 5; 
    context.strokeStyle = 'blue'; 
    context.stroke(); 
</script> 

有关详细信息,看看here

+0

真棒!谢谢!! – user2587454