Fabric.js ：更改一个或多个选择的正方形/矩形颜色

Question

我正在开发一个使用Fabric.js库的项目。我想知道如何更改当您想要选择一个或多个对象时出现的正方形/矩形。

就是下图中的蓝色矩形：

我已经在更改一些样式，例如对象选择的角颜色、边框颜色等等：

fabric.Object.prototype.selection = !HelperJSViewBag.getValue("isMobile") && true;
fabric.Object.prototype.selectionColor = HelperJSViewBag.getValue("selectionColor").length > 0 ? HelperJSViewBag.getValue("selectionColor") : 'rgba(255,119,0,0.3)';
fabric.Object.prototype.rotationCursor = HelperJSViewBag.getValue('cursor_rotacao').length > 0 ? HelperJSViewBag.getValue('cursor_rotacao') : "crosshair";
fabric.Object.prototype.cornerSize = HelperJSViewBag.getValue("isMobile") ? (HelperJSViewBag.getValue("containerCornerSizeMobile") > 0 ? HelperJSViewBag.getValue("containerCornerSizeMobile") : 14) : (HelperJSViewBag.getValue("containerCornerSize") > 0 ? HelperJSViewBag.getValue("containerCornerSize") : 10);
fabric.Object.prototype.cornerColor = HelperJSViewBag.getValue("containerCornerColor").length > 0 ? HelperJSViewBag.getValue("containerCornerColor") : '#eee';
fabric.Object.prototype.borderColor = fabric.Object.prototype.cornerColor;
fabric.Object.prototype.transparentCorners = false;
fabric.Object.prototype.borderScaleFactor = HelperJSViewBag.getValue("borderScaleFactor") > 0 ? HelperJSViewBag.getValue("borderScaleFactor") : 1;
fabric.Object.prototype.hasRotatingPoint = !HelperJSViewBag.getValue("isMobile") && true;
fabric.Object.prototype.rotatingPointOffset = HelperJSViewBag.getValue("isMobile") ? 20 : 35;

Answer 1

var canvas = new fabric.Canvas('canvas');
fabric.Canvas.prototype.set({
 selectionColor : 'rgba(255,0,0,0.3)',
 selectionBorderColor :  'rgba(0, 255, 0, 0.3)',
 selectionLineWidth : 10,
 selectionDashArray : [3,3]
});

canvas {
    border: 2px dotted green;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.16/fabric.min.js"></script>
<canvas id="canvas" width="400" height="400"></canvas>

您可以覆盖这些选择属性。