将 Google Api 多边形保存为 openlayers 字符串

Question

我想将用户绘制的多边形保存到字符串中，例如：

"SRID=4326;GEOMETRYCOLLECTION(POLYGON((......)))"

有办法吗？ 我不想使用 google API

中的 encodeString

谢谢

Answer 1

我找到了这个解决方案，希望这也能帮助遇到与我相同问题的任何人。

Convert Google Maps Polygon (API V3) to Well Known Text (WKT) Geometry Expression

function GMapPolygonToWKT(poly) {
    // Start the Polygon Well Known Text (WKT) expression
    wkt = "SRID=4326;GEOMETRYCOLLECTION(POLYGON(";

    var paths = poly.getPaths();

    for(var i=0; i<paths.getLength(); i++) {
        var path = paths.getAt(i);

        // Open a ring grouping in the Polygon Well Known Text
        wkt += "(";
        for(var j=0; j<path.getLength(); j++) {

            // setCenteradd each vertice and anticipate another vertice (trailing comma)
            wkt += path.getAt(j).lng().toString()
                + " "
                + path.getAt(j).lat().toString()
                +",";
        }
        // Also close the ring grouping and anticipate another ring (trailing comma)
        wkt += path.getAt(0).lng().toString()
            + " "
            + path.getAt(0).lat().toString()
            + "),";
    }
    // resolve the last trailing "," and close the Polygon
    wkt = wkt.substring(0, wkt.length - 1) + "))";
    return wkt;
}

这是 GeoDjango postgis 数据库的有效字符串。