D
                controls: ol.control.defaults({
                    attributionOptions: ({
                        collapsible: true
                    })
                }),
                view: new ol.View({
                    center: [110, 30],
                    zoom: 4,
                    projection: 'EPSG:4326'
                }),
                layers:[TiandiMap_vectIGS,TiandiMap_ciaIGS]
            });

            //添加绘制图层
            drawSource = new ol.source.Vector({
        