Javascript OpenLayers 2：仅使用两点绘制路径

我想画一条不超过2点的路径。在第二点上，我希望路径完成

谁能帮助我如何在openlayers 2中实现这个功能

我尝试了这段代码，但它给出了错误，尽管行创建得很好

        _singleLineControl = new OpenLayers.Control.DrawFeature(
            _singleLineLayer,
            OpenLayers.Handler.Path,
            {
                eventListeners: { "featureadded": drawingFinished },
                callbacks: {
                    point: function (pointGeometry, lineGeometry) {
                        var numPoints = lineGeometry.getVertices().length;
                        if (numPoints == 3) {
                            this.drawFeature(lineGeometry);
                        }
                    }
                }
            });
        viewer.addControl(_singleLineControl);
        _singleLineControl.handler.single = true;
        _singleLineControl.handler.freehand = false;
        _singleLineControl.deactivate();

自己找到了解决方案：）使用

maxVertices

        // single line drawing control
        _singleLineControl = new OpenLayers.Control.DrawFeature(
            _singleLineLayer,
            OpenLayers.Handler.Path,
            {
                eventListeners: { "featureadded": drawingFinished },
                handlerOptions: {
                    maxVertices: 2,
                    single: true,
                    freehand: false,
                }
            });
        viewer.addControl(_singleLineControl); 
        _singleLineControl.deactivate();