<canvas style="background-color:#efefef;" width="600" height="600" id="canvas"> </canvas> <script type="text/javascript"> $('#canvas').drawArc({ layer: true, draggable: true, fillStyle: '#36c', x: 300, y: 300, radius: 50, }); </script> code like this, if I set canvas width 300px,height 300px, like this " <canvas style="background-color:#efefef;" width="600" height="600" style="width:300px;height:300px;" id="canvas">",and then can't drag again.