Fabric.js loadFromJSON不工作与RGBA填充

Question

我有一个简单的画布上我加入的形状（三角形，圆形，矩形）。我已经使用了支持rgba的光谱颜色选择器，并且我正在根据所选颜色设置形状的填充。到目前为止，一切正常。现在我出口画布作为JSON，

var json = JSON.stringify(canvas); 
console.log(json); 

这JSON输出稍后将保存到数据库中，但对于测试目的，我复制从控制台的JSON和使用它作为跟随，

canvas.loadFromJSON('{"objects":[{"type":"circle","originX":"center","originY":"center","left":400,"top":200,"width":100,"height":100,"fill":{"_originalInput":{"h":"0%","s":"100%","v":"100%","a":0.13},"_r":255,"_g":0,"_b":0,"_a":0.13,"_roundA":0.13,"_format":"rgb","_ok":true,"_tc_id":3288},"stroke":{"_originalInput":{"h":"0%","s":"0%","v":"0%","a":1},"_r":0,"_g":0,"_b":0,"_a":1,"_roundA":1,"_format":"rgb","_ok":true,"_tc_id":3783},"strokeWidth":1,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":0.4,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"radius":50,"startAngle":0,"endAngle":6.283185307179586},{"type":"triangle","originX":"left","originY":"top","left":583,"top":89,"width":50,"height":50,"fill":{"_originalInput":{"h":"17.374213836477992%","s":"86.88524590163934%","v":"95.68627450980392%","a":0.34},"_r":235.01046366720004,"_g":243.98400000000004,"_b":32.01070080000003,"_a":0.34,"_roundA":0.34,"_format":"hex","_ok":true,"_tc_id":2503},"stroke":"rgb(0, 0, 0)","strokeWidth":6,"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","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0},{"type":"rect","originX":"left","originY":"top","left":485,"top":196,"width":50,"height":50,"fill":"#1d128f","stroke":null,"strokeWidth":1,"strokeDashArray":null,"strokeLineCap":"butt","strokeLineJoin":"miter","strokeMiterLimit":10,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":0.4,"shadow":null,"visible":true,"clipTo":null,"backgroundColor":"","fillRule":"nonzero","globalCompositeOperation":"source-over","transformMatrix":null,"skewX":0,"skewY":0,"rx":0,"ry":0}],"background":""}'); 
canvas.renderAll(); 

我面临的问题是，由于导出的JSON具有rgba值，所以当形状呈现在画布上时，填充是黑色的。画布忽略了JSON字符串中的rgba值。

然而，当我使用下面的JSON字符串（其中有填充“绿色”和“红”），那么形状呈现细跟颜色绿色和红色。

canvas.loadFromJSON('{"objects":[{"type":"rect","left":50,"top":50,"width":20,"height":20,"fill":"green","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"rx":0,"ry":0},{"type":"circle","left":100,"top":100,"width":100,"height":100,"fill":"red","overlayFill":null,"stroke":null,"strokeWidth":1,"strokeDashArray":null,"scaleX":1,"scaleY":1,"angle":0,"flipX":false,"flipY":false,"opacity":1,"selectable":true,"hasControls":true,"hasBorders":true,"hasRotatingPoint":false,"transparentCorners":true,"perPixelTargetFind":false,"radius":50}],"background":"rgba(0, 0, 0, 0)"}'); 

这是一个在fabric.js中的错误，或者我做错了什么？

Answer 1

确定。我已经发现它为什么会发生。问题是我如何设置形状对象的颜色。我使用频谱颜色选择器，并使用以下代码来初始化频谱，并且还添加代码，当在光谱的ColorPicker则选择的颜色它也被改变为在画布上所选择的形状的对象。

$(".spectrumColor").spectrum({ 
     showAlpha: true, 
     showButtons: false, 
     showPalette: true, 
     palette: defaultPallete, 
     allowEmpty: true, 
     showInput: true, 
     move: function (color) { 

      var selectedObject = canvas.getActiveObject(); 
      if (selectedObject != null) { 
       if ($(this).attr('id') == "FillColor") { 
        selectedObject.set('fill', color); 
        canvas.renderAll(); 
       } 
       else if ($(this).attr('id') == "StrokeColor") { 
        selectedObject.set('stroke', color); 
        canvas.renderAll(); 
       } 
      } 
     } 
    }); 

这里的问题是与这条线，

selectedObject.set('stroke', color); 

我已通过全彩色对象从光谱的织物形状对象。当我检查在控制台颜色的值，则它是简单的RGB字符串“RGB（255，0，0）”，但是当完整的对象被分配到织物的形状的对象则是加入HSV（色调，饱和度和亮度）与RGB沿弦向矩阵形状对象像这样，

fill":{"_originalInput":{"h":"0%","s":"100%","v":"100%","a":0.13},"_r":255,"_g":0,"_b":0,"_a":0.13 

如HSV无法识别由Fabric.js因此它被渲染为黑色的颜色的形状的物体。为了解决这个问题，我不得不更换，

selectedObject.set('stroke', color); 

与

selectedObject.set('stroke', color.toRgbString());