aneObj.prototype.draw=function?()?{
????for(var?i=0;i<this.num;i++){
????????//begin?moveto?lineto?stroke?strokestyle?linewigth?linecap?globalAlpha?closepath
????????ctx2.beginPath();//?？L制在canvas2上
????????ctx2.moveTo(this.x[i],canHeight);//繪制起始點?x?y
????????ctx2.lineTo(this.x[i],canHeight-this.len[i]);
????????ctx2.strokeStyle="purple";//紫色?在stroke之前
????????ctx2.stroke();//首先告訴筆觸顏色?才能用stroke畫
????????ctx2.lineWidth=10;
????????ctx2.lineCap="round";
????????ctx2.globalAlpha=0.6;
????????ctx2.closePath();
????}
};

我也是海葵的高度和背景圖片一樣高~~~~~~

最好是貼代碼，感覺是你繪制?？厦娉霈F問題，lineTo()參數看是不是有誤