我正在尝试使用fabric.js将数据保存到JSON中，并将其加载回画布，但是在尝试以下简单代码时出现错误：
canvas.add(new fabric.Rect({ width: 50, height: 50, fill: 'red', top: 100, left: 100 }));
var c = canvas.toJSON();
canvas.clear();
canvas.loadFromJSON(c);
我得到：
SyntaxError: JSON.parse: unexpected character
[Break On This Error] var Cufon=(function(){var k=function()....Image.fromElement.async=true})(this);
当我使用自己的JSON时，它可以很好地验证，但当我使用由fabric的方法canvas.toJSON()输出的任何内容时，仍然会出现错误。是否有人有工作示例，可以将先前画布状态保存的数据加载回空画布中的fabric.js？非常感谢！
fabric.Canvas#toJSON返回的实际上是一个对象，而不是一个JSON字符串。
如果这让您感到困惑，我们表示抱歉。
之所以会这样运作，是因为JSON.stringify支持自定义序列化；您只需要传递一个具有toJSON方法的对象即可。这正是我在fabric中所做的-- fabric.Canvas具有toJSON方法，它本质上是toObject方法的别名。
这使我们可以通过执行以下简单操作来序列化画布：
JSON.stringify(canvas);
..其中canvas是一个指向fabric.Canvas实例的引用。
toObject 和 toDatalessObject（以及 toJSON 和 toDatalessJSON）之间的区别在于，toDatalessObject 返回 "url" 而不是实际的路径数据。这样做是为了节省表示带有大尺寸形状的画布的大小。如果您加载大型 SVG 形状，其路径数据可能会成为数百万字符字符串。如果以后需要序列化此数据（比如说，为保存目的），用 svg 形状的 URL 替换路径数据将更加合理。想象一下必须把这样巨大的字符串来回上传/下载到服务器上。
所以，代替这个：
{ "angle" : 3,
"fill" : "#00274D",
"flipX" : false,
"flipY" : false,
"height" : 115,
"left" : 353,
"opacity" : 1,
"overlayFill" : null,
"path" : [ [ "M",
67.390000000000001,
22.390000000000001
],
[ "c",
2.5899999999999999,
-0.42999999999999999,
5.1100000000000003,
1.4399999999999999,
5.54,
4.1799999999999997
],
[ "c",
0.42999999999999999,
2.6600000000000001,
-1.3,
5.2599999999999998,
-3.8900000000000001,
5.6900000000000004
],
[ "c",
-1.8,
0.28999999999999998,
-3.6000000000000001,
-0.57999999999999996,
-4.6100000000000003,
-2.02
],
[ "L",
44.5,
34.560000000000002
],
[ "l",
10.869999999999999,
59.619999999999997
],
[ "c",
17.420000000000002,
-4.46,
26.059999999999999,
-14.18,
27.5,
-29.02
],
[ "l",
-10.01,
-0.71999999999999997
],
[ "L",
88.700000000000003,
51.909999999999997
],
[ "l",
9.4299999999999997,
21.239999999999998
],
[ "c",
-3.3799999999999999,
-1.95,
-5.9000000000000004,
-5.1100000000000003,
-9.2899999999999991,
-7.0599999999999996
],
[ "c",
-0.28999999999999998,
25.059999999999999,
-27.140000000000001,
32.759999999999998,
-33.770000000000003,
47.950000000000003
],
[ "C",
44.420000000000002,
100.08,
26.5,
114.77,
6.9100000000000001,
82.799999999999997
],
[ "L",
0,
92.450000000000003
],
[ "l",
1.51,
-21.600000000000001
],
[ "l",
19.66,
4.6799999999999997
],
[ "l",
-9.4299999999999997,
3.6699999999999999
],
[ "c",
7.4900000000000002,
11.59,
17.57,
19.870000000000001,
36.43,
16.420000000000002
],
[ "L",
36.219999999999999,
36.57
],
[ "l",
-18.649999999999999,
2.3799999999999999
],
[ "c",
-0.14000000000000001,
2.1600000000000001,
-1.73,
4.0300000000000002,
-3.8900000000000001,
4.3899999999999997
],
[ "c",
-2.5899999999999999,
0.42999999999999999,
-5.04,
-1.4399999999999999,
-5.54,
-4.0999999999999996
],
[ "c",
-0.42999999999999999,
-2.7400000000000002,
1.3,
-5.2599999999999998,
3.8900000000000001,
-5.6900000000000004
],
[ "c",
1.9399999999999999,
-0.35999999999999999,
3.8900000000000001,
0.65000000000000002,
4.9000000000000004,
2.2999999999999998
],
[ "l",
17.93,
-4.8200000000000003
],
[ "l",
-1.3700000000000001,
-6.8399999999999999
],
[ "c",
-4.8200000000000003,
-0.79000000000000004,
-8.9299999999999997,
-4.75,
-9.7899999999999991,
-10.08
],
[ "c",
-1.1499999999999999,
-6.6200000000000001,
3.1000000000000001,
-12.890000000000001,
9.4299999999999997,
-13.970000000000001
],
[ "c",
6.4100000000000001,
-1.01,
12.460000000000001,
3.46,
13.539999999999999,
10.08
],
[ "c",
0.85999999999999999,
5.1799999999999997,
-1.5800000000000001,
10.15,
-5.6900000000000004,
12.6
],
[ "l",
1.8700000000000001,
6.1200000000000001
],
[ "l",
20.739999999999998,
-2.8799999999999999
],
[ "C",
64.010000000000005,
24.260000000000002,
65.519999999999996,
22.75,
67.390000000000001,
22.390000000000001
],
[ "L",
67.390000000000001,
22.390000000000001
],
[ "z" ],
[ "M",
33.909999999999997,
5.1799999999999997
],
[ "c",
-3.46,
0.57999999999999996,
-5.7599999999999998,
3.96,
-5.1100000000000003,
7.5599999999999996
],
[ "c",
0.57999999999999996,
3.6000000000000001,
3.8900000000000001,
6.0499999999999998,
7.2699999999999996,
5.4699999999999998
],
[ "c",
3.46,
-0.57999999999999996,
5.7599999999999998,
-3.96,
5.1799999999999997,
-7.5599999999999996
],
[ "C",
40.609999999999999,
7.0499999999999998,
37.369999999999997,
4.6100000000000003,
33.909999999999997,
5.1799999999999997
],
[ "z" ]
],
"scaleX" : 3.0299999999999998,
"scaleY" : 3.0299999999999998,
"selectable" : true,
"stroke" : null,
"strokeWidth" : 1,
"top" : 220,
"type" : "path",
"width" : 99
}
你会得到这个：
{ "angle" : 3,
"fill" : "#00274D",
"flipX" : false,
"flipY" : false,
"height" : 115,
"left" : 353,
"opacity" : 1,
"overlayFill" : null,
"path" : "http://example.com",
"scaleX" : 3.0299999999999998,
"scaleY" : 3.0299999999999998,
"selectable" : true,
"stroke" : null,
"strokeWidth" : 1,
"top" : 220,
"type" : "path",
"width" : 99
}
请注意数据的大小，通过使用URL替换路径块，它变得相对较小。
这仅是一个非常简单的形状表示。
唯一的要求是在调用toDatalessObject/toDatalessJSON之前，使用setSourcePath方法设置对象的“sourcePath”（“sourcePath”内部被复制到“path”）。
希望这能解决一些问题。
var js = JSON.stringify(canvas); canvas.clear(); canvas.loadFromJSON(js);我得到了“引用错误”。对于我的解决方法，我保存JSON，然后遍历它，查看每个对象的类型，创建相应类型的新织物对象，使用json中的参数进行初始化，然后添加它... - Regis ZalemansavedDataDLJSON = c1.toDatalessJSON()替换为savedDataDLJSON = JSON.stringify(c1.toDatalessJSON())。 - kangax