android获取并解析Google路线

Question

google Directions
API

现在，我阅读了本指南，我可以构建一个正确的请求来接收包含从地址A到地址B的路线的xml文件。我需要一些说明和示例，以了解如何读取此xml在Android
MapView上绘制获得的路线。我也想知道在xml中代表这个标签的是什么：

<overview_polyline>
<points>
a~l~Fjk~uOnzh@vlbBtc~@tsE`vnApw{A`dw@~w\|tNtqf@l{Yd_Fblh@rxo@b}
@xxSfytAblk@xxaBeJxlcBb~t@zbh@jc|Bx}C`rv@rw|@rlhA~dVzeo@vrSnc}Axf]fjz@
xfFbw~@dz{A~d{A|zOxbrBbdUvpo@`cFp~xBc`Hk@nurDznmFfwMbwz@bbl@lq~@lo
Ppxq@bw_@v|{CbtY~jGqeMb{iF|n\~mbDzeVh_Wr|Efc\x`Ij{kE}mAb~uF{cNd}xBjp]
fulBiwJpgg@|kHntyArpb@bijCk_Kv~eGyqTj_|@`uV`k|DcsNdwxAott@r}q@_gc@nu`CnvH
x`k@dse@j|p@zpiAp|gEicy@`omFvaErfo@igQxnlApqGze~AsyRzrjAb__@ftyB}pIlo_B
flmA~yQftNboWzoAlzp@mz`@|}_@fda@jakEitAn{fB_a]lexClshBtmqAdmY_hLxiZd~XtaBndgC
</points>
<levels>BBBAAAAABAABAAAAAABBAAABBAAAABBAAABABAAABABBAABAABAAAABABABABBABAABB</levels> 
</overview_polyline>

谢谢

Answer 1

我在网上找到了这个示例，我将尝试使用它。折线解码示例

private List<GeoPoint> decodePoly(String encoded) {

  List<GeoPoint> poly = new ArrayList<GeoPoint>();
  int index = 0, len = encoded.length();
  int lat = 0, lng = 0;

  while (index < len) {
      int b, shift = 0, result = 0;
      do {
          b = encoded.charAt(index++) - 63;
          result |= (b & 0x1f) << shift;
          shift += 5;
      } while (b >= 0x20);
      int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
      lat += dlat;

      shift = 0;
      result = 0;
      do {
          b = encoded.charAt(index++) - 63;
          result |= (b & 0x1f) << shift;
          shift += 5;
      } while (b >= 0x20);
      int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
      lng += dlng;

      GeoPoint p = new GeoPoint((int) (((double) lat / 1E5) * 1E6),
           (int) (((double) lng / 1E5) * 1E6));
      poly.add(p);
  }

  return poly;
}