html5javascriptcanvas照着抄都找不出错在哪，求助

liuganglove2018 · 发表于 2024-3-19 20:27

html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
#myCanvas{border:1px solid red;}
</style>
</head>
<body>
<canvas id="myCanvas" width="500" height="300"></canvas>
</body>
<script src="mycanvas.js">
</script>
</html>
---------------------------------------------------------
js

var canvas=document.getElementById('myCanvas');
var pen=canvas.getContext('2d');

pen.lineWidth=1;
pen.strokeStyle="red";

var mousePress=false;
var last=null;

function pos(event){
var ex,ey;
ex=event.clientX;
ey=event.clientY;
return(x:ex,y:ey)
}

function start(event){
mousePress=true;

}

function draw(event){
if(!mousePress) return;
var xy=pos(event);
if(last != null){
pen.beginPath();
pen.moveTo(last.x,last.y);
pen.lineto(xy.x,xy.y);
pen.stroke();
}
last=xy;
}

function finish(event){
mousePress=false;
last=null;
}
canvas.onmousedown=start;
canvas.onmousemove=draw;
canvas.onmouseup=finish;

lengong · 发表于 2024-3-19 20:46

liuganglove2018 · 发表于 2024-3-19 21:02

lengong 发表于 2024-3-19 20:46
function pos(event){
var ex,ey;
ex=event.clientX;

大佬是怎么这么厉害的，人工看出来的吗，现在我怀疑自己是不是脑袋不好使，呜呜

lengong · 发表于 2024-3-19 21:10

新手？没调试过页面？浏览器上有报错提示

steven026 · 发表于 2024-3-20 12:13

把代码随便丢进一个代码编辑器都能报错
这里应该是{x:ex,y:ey}

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[求助] html5javascriptcanvas照着抄都找不出错在哪，求助