我有这个JSON：https://codepen.io/dhavalsisodiya/pen/RJNNXw
那个json有另外的属性作为textAnchor。现在的问题是，当我试图将json加载到画布上时，textAnchor属性不会包含在画布对象中。
您可以在此处查看示例：https://codepen.io/dhavalsisodiya/pen/VdYLwo 正如你在canavs上看到的那样，textAnchor没有加载到画布上。
那么如何解决这个问题？
var json = '{"version":"2.2.2","objects":[{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":12.5,"top":67.32,"width":382.12,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1.51,"scaleY":1.87,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{First_Name} {Last_Name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":8.5,"top":150,"width":585,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{first_name} {last_name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":7.5,"top":187,"width":587,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{address_1}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"}]}';
var canvas1 = new fabric.Canvas('canvas1');
canvas1.loadFromJSON(json);
// re-render the canvas
canvas1.renderAll();
console.log(JSON.stringify(canvas1));<script type="text/javascript" src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<body>
<canvas id="canvas1" style="border:1px solid black"></canvas>
注意：我使用此问题添加了textAnchor支持：How to use text-anchor : middle in fabric js
同样根据文档：http://fabricjs.com/fabric-intro-part-3
我们使用附加属性 - ＆＃34; name＆＃34;扩展了对象的现有toObject方法，因此该属性现在是toObject输出的一部分，因此出现在canvas JSON表示中。值得一提的另一件事是，如果你扩展这样的对象，你也要确保对象＆＃34; class＆＃34; （在这种情况下，fabric.Rect）在＆＃34; stateProperties＆＃34;中具有此属性。数组，以便从字符串表示中加载画布将解析并正确地将其添加到对象。
所以不确定js的哪一部分需要修改？
答案 0 :(得分：2)
正如tutorial中提到的那样，您可以覆盖toobject方法以包含自定义属性。
fabric.Textbox.prototype.toObject = (function(toObject) {
return function() {
return fabric.util.object.extend(toObject.call(this), {
textAnchor: this.textAnchor
});
};
})(fabric.Textbox.prototype.toObject);
<强> 样本
var json = '{"version":"2.2.2","objects":[{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":12.5,"top":67.32,"width":382.12,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1.51,"scaleY":1.87,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{First_Name} {Last_Name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":8.5,"top":150,"width":585,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{first_name} {last_name}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"},{"type":"textbox","version":"2.2.2","originX":"left","originY":"top","left":7.5,"top":187,"width":587,"height":24.86,"fill":"rgb(0,0,0)","stroke":null,"strokeWidth":0,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","paintFirst":"fill","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"text":"{address_1}","fontSize":22,"fontWeight":"normal","fontFamily":"Times New Roman","fontStyle":"normal","lineHeight":1.16,"underline":false,"overline":false,"linethrough":false,"textAlign":"center","textBackgroundColor":"","charSpacing":0,"minWidth":20,"styles":{},"textAnchor":"middle"}]}';
var canvas1 = new fabric.Canvas('canvas1');
fabric.Textbox.prototype.toObject = (function(toObject) {
return function() {
return fabric.util.object.extend(toObject.call(this), {
textAnchor: this.textAnchor
});
};
})(fabric.Textbox.prototype.toObject);
canvas1.loadFromJSON(json,function(){
// re-render the canvas
canvas1.renderAll();
console.log(JSON.stringify(canvas1));
});<script type="text/javascript" src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<body>
<canvas id="canvas1" style="border:1px solid black"></canvas>
答案 1 :(得分：0)
我正在使用2.4.6并解决问题。
canvas.loadFromJSON(Json, function ()
{
debugger;
canvas.renderAll();
console.log(JSON.stringify(canvas));
var json = canvas.toJSON(['selectable', 'name', 'ownType', 'ddlValue', 'lockScalingX']);
console.log(JSON.stringify(json))
});