看了半天看
因为手机端是没有mouse = =

this.canvas.onmousedown = function (e) { _this.downEvent(e)};  
this.canvas.onmousemove = function (e) { _this.moveEvent(e)};  
this.canvas.onmouseup = function (e) { _this.upEvent(e)};  
this.canvas.onmouseout = function (e) { _this.upEvent(e)};  

改为-->

this.canvas.addEventListener('touchstart', function (e) { _this.downEvent(e)});  
this.canvas.addEventListener('touchmove', function (e) { _this.moveEvent(e)});  
this.canvas.addEventListener('touchend ', function (e) { _this.upEvent(e)});  

试一下~ ps:因为我现在没有服务器测不了~

移动端要用touch系列事件,而不是mouse

移动端用touch事件，这样试试呢
this.canvas.addEventListener("touchstart",function(e){
 //do something
}