Html5 Canvas 画板实例详解

myCanvas.lineWidth = 5
myCanvas.strokeStyle = "blue";
myCanvas.lineCap = "round";
var paint = 0 ;  
$( "#myCanvas" ).mousedown(function(e){
 var mouseX = e.pageX - this.offsetLeft;
 var mouseY = e.pageY - this.offsetTop;
 paint = 1;
 myCanvas.moveTo(mouseX, mouseY);
});
$( "#myCanvas" ).mouseup(function(e){
 paint = 0;
});
$( "#myCanvas" ).mousemove(function(e){
 var mouseX = e.pageX - this.offsetLeft;
 var mouseY = e.pageY - this.offsetTop;
 if( paint ){
  myCanvas.lineTo(mouseX, mouseY);
  myCanvas.stroke();
 }
});