解析KML文件并提取coordinates中的经纬度坐标信息

从googleEarh导出的kml文件

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2">
<Document>
  <!-- Begin Style Definitions -->
  <Style id="line1">
    <LineStyle>
      <color>FF808080</color>
      <width>1</width>
    </LineStyle>
  </Style>
  <Folder>
    <name>Line Features</name>
    <description>Line Features</description>
    <Placemark>
      <description>Unclassified Line Feature</description>
      <styleUrl>#line1</styleUrl>
      <LineString>
        <coordinates>
          115.9676728167,40.4840735806,0
          115.9537842111,40.4823857889,0
          115.9563131444,40.4703987611,0
          115.9551753833,40.4662973972,0
          115.9554458000,40.4636396361,0
          115.9397187972,40.4622803889,0
          115.9405904556,40.4562066889,0
          115.9408371611,40.4549313694,0
          115.9422346222,40.4538901583,0
          115.9448324639,40.4514630028,0
          115.9574561306,40.4524817889,0
          115.9619367944,40.4513946639,0
        </coordinates>
      </LineString>
    </Placemark>
  </Folder>
</Document>
</kml>

做工程中遇到需要解析kml文件并提取其中的经纬度坐标信息的需求，从网上查了一圈资料发现都不好用，干脆自己写，用正则表达式regex和split(）方法实现了坐标信息提取功能。

主要遇到的问题是coordinates中的InnerText文本中有\t  \n \r \f 或多空格问题，需要将这些因素排除。

\f 匹配一个换页符
\n 匹配一个换行符
\r 匹配一个回车符
\t 匹配一个制表符

这些符号用正则表达式字符替换方式直接清除

Regex reg = new Regex("\f|\n|\r|\t");
string modified = reg.Replace(tt, "");

多空格问题用split的StringSplitOptions.RemoveEmptyEntries来清除

string[] ss = modified.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);//清除空格

这样就能得到纯粹的x,y,z字符串数组了.OK。

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想了2种思路，目前第1种思路已经测试通过了，第2种思路懒得写了，哪位如果有兴趣实现了的话告诉我一声喔，，也算是饮水思源啦。

************************************************************************************************************************************************

代码如下：

private void KMLFileLoadButton_Click(object sender, EventArgs e)
{// 读取googleEarth的导出的kml/kmz路径文件
            OpenFileDialog dlg = new OpenFileDialog();
            dlg.Filter = "KML文件(*.kml)|*.kml|所有文件|*.*";
            if (dlg.ShowDialog() != DialogResult.OK)
                return;
            string destPath = dlg.FileName;//CopyToRelavitePath(dlg.FileName);
            if (destPath == null)
                return;

XmlDocument xmldoc = new XmlDocument();
            xmldoc.Load(destPath);
            XmlElement root = xmldoc.DocumentElement;
            /////规范命名空间
            XmlNode _document = root.GetElementsByTagName("Document")[0];
            XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmldoc.NameTable);
            if (_document== null || _document.Attributes["xmlns"]==null)
            {
                nsmgr.AddNamespace("ns", root.Attributes["xmlns"].Value);
            }
            else
            {
                nsmgr.AddNamespace("ns", _document.Attributes["xmlns"].Value);
            }

NGlbLine geo = new NGlbLine(3, false);
            XmlNodeList xmlmark = root.GetElementsByTagName("Placemark");
            for (int m = 0; m < xmlmark.Count; m++)
            {
                XmlNodeList xmlmarkChilds = xmlmark[m].ChildNodes;
                for (int n = 0; n < xmlmarkChilds.Count; n++)
                {
                    XmlNode node = xmlmarkChilds[n];
                    if (node.Name == "LineString" || node.Name == "LineRing")
                    {
                        XmlNode coordsNode = node.FirstChild;
                        while (coordsNode != null && coordsNode.Name != "coordinates")
                        {
                            coordsNode = coordsNode.NextSibling;
                        }
                        if (coordsNode == null)
                            continue;
                        // 思路1 ：用正则表达式去除字符串首位的制表符、换行符等符号，然后用' '来划分为string[]
                        string tt = coordsNode.InnerText;
                        Regex reg = new Regex("\f|\n|\r|\t");
                        string modified = reg.Replace(tt, "");
                        string[] ss = modified.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);//清除空格
                        for (int cc = 0; cc < ss.Length; cc++)
                        {
                            string[] aa = ss[cc].Split(',');
                            if (aa.Length == 3)                           
                                geo.AddPoint(Convert.ToDouble(aa[0]), Convert.ToDouble(aa[1]), Convert.ToDouble(aa[2]));                            
                            else if (aa.Length == 2)                            
                                geo.AddPoint(Convert.ToDouble(aa[0]), Convert.ToDouble(aa[1]), 0);                                                       
                        }
                        
                        // 思路2 ：用regex正则表达式匹配 类似 115.9676728167,40.4840735806,0的样式字段

}
                }
            }

　　.............................................
 }