beginPath,moveTo,lineTo, stroke,strokeStyle,lineWidth,lineCap,globalAlpha,closePath

图片显示很大很糊

正确：<canvas id="canvas1" width="700px" height="400px"></canvas>

错误：<canvas id="canvas2" ></canvas>

错误：#canvas1 { position: absolute; left: 300px; top: 100px; z-index: 0; width: 700px; height: 400px; }

在js中获取canvas的宽高：

正确：canWidth = can1.width;

错误：canWidth = can1.style.width;

大于运动 明显与鼠标不符

我之前已知图片显示很大很糊，大鱼代码检查不出问题。改了canvas参数居然神奇的好了哈哈

正确：<canvas id="canvas1" width="700px" height="400px"></canvas>

错误：<canvas id="canvas2" ></canvas>

错误：#canvas1 { position: absolute; left: 300px; top: 100px; z-index: 0; width: 700px; height: 400px; }

在js中获取canvas的宽高：

正确：canWidth = can1.width;

错误：canWidth = can1.style.width;