我非常擅长为chrome创建扩展,现在我只是想乱搞并创建一个可以打开并绘制的简单画布。
当我将 popup.html 加载为普通网页时,一切似乎都运行正常,但是当我在Chrome中打开扩展程序时,没有任何功能。
{
"manifest_version": 2,
"name": "Sketchpad",
"description": " ",
"version": "0.1",
"browser_action": {
"default_icon": "icon.png",
"default_popup": "popup.html"
}
}
<!doctype html>
<html>
<head>
<title>Drawing Pad</title>
<style>
body {
font-family: "Segoe UI", "Lucida Grande", Tahoma, sans-serif;
font-size: 100%;
}
.color {display: inline-block;}
#can {
cursor: url(pencil.png), auto;
}
</style>
<script src="canvas.js"></script>
</head>
<body onload="init()">
<canvas id="can" width="400" height="400" style="border:2px solid;"></canvas><br>
<div style="display: inline-block;">Choose Color
<div class="color" style="width: 10px; height: 10px; background: green;" id="green" onclick="color(this)"></div>
<div class="color" style="width: 10px; height: 10px; background: blue;" id="blue" onclick="color(this)"></div>
<div class="color" style="width: 10px; height: 10px; background: red;" id="red" onclick="color(this)"></div>
<div class="color" style="width: 10px; height: 10px; background: yellow;" id="yellow" onclick="color(this)"></div>
<div class="color" style="width: 10px; height: 10px; background: orange;" id="orange" onclick="color(this)"></div>
<div class="color" style="width: 10px; height: 10px; background: black;" id="black" onclick="color(this)"></div>
</div>
<div style="display: inline-block;">Eraser
<div style="width:15px;height:15px;background:white;border:2px solid;display: inline-block" id="white" onclick="color(this)"></div>
</div><br>
<input type="button" value="Clear" id="clr" size="23" onclick="erase()">
</body>
</html>
var canvas, ctx, flag = false,
prevX = 0,
currX = 0,
prevY = 0,
currY = 0,
dot_flag = false;
var x = "black",
y = 2;
function init() {
canvas = document.getElementById('can');
ctx = canvas.getContext("2d");
w = canvas.width;
h = canvas.height;
canvas.addEventListener("mousemove", function (e) {
findxy('move', e)
}, false);
canvas.addEventListener("mousedown", function (e) {
findxy('down', e)
}, false);
canvas.addEventListener("mouseup", function (e) {
findxy('up', e)
}, false);
canvas.addEventListener("mouseout", function (e) {
findxy('out', e)
}, false);
}
function color(obj) {
switch (obj.id) {
case "green":
x = "green";
break;
case "blue":
x = "blue";
break;
case "red":
x = "red";
break;
case "yellow":
x = "yellow";
break;
case "orange":
x = "orange";
break;
case "black":
x = "black";
break;
case "white":
x = "white";
break;
}
if (x == "white") y = 14;
else y = 2;
}
function draw() {
ctx.beginPath();
ctx.moveTo(prevX, prevY);
ctx.lineTo(currX, currY);
ctx.strokeStyle = x;
ctx.lineWidth = y;
ctx.stroke();
ctx.closePath();
}
function erase() {
ctx.clearRect(0, 0, w, h);
}
function findxy(res, e) {
if (res == 'down') {
prevX = currX;
prevY = currY;
currX = e.clientX - canvas.offsetLeft;
currY = e.clientY - canvas.offsetTop;
flag = true;
dot_flag = true;
if (dot_flag) {
ctx.beginPath();
ctx.fillStyle = x;
ctx.fillRect(currX, currY, 2, 2);
ctx.closePath();
dot_flag = false;
}
}
if (res == 'up' || res == "out") {
flag = false;
}
if (res == 'move') {
if (flag) {
prevX = currX;
prevY = currY;
currX = e.clientX - canvas.offsetLeft;
currY = e.clientY - canvas.offsetTop;
draw();
}
}
}
在做了一些研究后,我觉得我的js代码格式化方式有问题,但我无法确定这是什么。对不起,很长的帖子和感谢,任何帮助表示赞赏。
答案 0 :(得分:2)
你不能将javascript代码放在goolge-chrome-extension中的html文件中。
替换
<body onload="init()">
使用:
document.body.addEventListener('load', function () {...})
有关详细信息,请参阅contentSecurityPolicy。
答案 1 :(得分:1)
此外,由于inline JS不被允许,onclick
<input type="button" value="Clear" id="clr" size="23" onclick="erase()">
应为<{p}}
<input type="button" value="Clear" id="clr" size="23">
并使用addEventListener绑定js文件中的事件。
document.addEventListener('DOMContentLoaded', function() {
var clear = document.getElementById('clr');
clear.addEventListener('click', function() {
erase();
});
});