? ? ? ? ? ? ? ? 工作需要，處理過一些KML文件，最近想借助KML梳理一下某些坐標點集，系統(tǒng)的了解一下KML文件的語法結構。（具體的格式解析用例放到最后）
? ? ? ? ? ? ? ? 這里我用<Point> 標記多個點的方式，整理我所收集到各省重點大學的坐標集合（舉個例子）。
? ? ? ? ? ? ? ? 然后把KML直接拖入到奧維地圖軟件中，選擇全部導入
? ? ? ? ? ? ? ? 做個簡單的記錄，把軟件工具和kml用例上傳到百度網(wǎng)盤：
????????????????鏈接：https://pan.baidu.com/s/16xdZmBEOgPPeEreQxS2zLw
????????????????提取碼：9xlr
????????????????基于XML，并定義了一些TAG用于規(guī)定地理數(shù)據(jù)的顯示方式。KML可用于定義的地理特征包括地點、描述、疊層、路徑和多邊形等。
? ??????基本格式
1 地點標記（Placemarks）
一個簡單的地點標記的KML代碼如下所示：
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
?<Placemark>???
<name>Simple placemark</name>???
<description>Attached to the ground. Intelligently places itself
?????? at the height of the underlying terrain.
</description>???
<Point>?????
<coordinates>-122.0822035425683,37.42228990140251,0</coordinates>???
</Point>?
</Placemark>
</kml>
它包括以下幾個部分：
（1）XML頭：<?xml version="1.0" encoding="UTF-8"?>
（2）KML命名空間定義：<kml xmlns="http://earth.google.com/kml/2.1">
（3）地點標記對象，包括：
名稱（name）：用于對地點標記進行注記；
描述（description）：對地點標記進行描述，“氣球（ballon）”中的顯示內容；
點（Point）：指定地點標記的位置。
2 使用HTML描述地點標記
有兩種方式來使用HTML描述地點標記，一種是直接在，<Snippet>和<BalloonStyle>中的<text>標記中寫入標準HTTP超鏈接地址，如www.google.com，這樣Google Earth 4.0及更高版本將利用Auto-Markup技術自動把它顯示為超鏈接。另一種是使用CDATA元素在標記中寫入自己的HTML標記語言，如下所示：
<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://earth.google.com/kml/2.1">
?<Document>
??? <Placemark>
????? <name>CDATA example</name>
????? <description>
??????? <![CDATA[
????????? <h1>CDATA Tags are useful!</h1>
????????? <p><font color="red">Text is <i>more readable</i> and
????????? <b>easier to write</b> when you can avoid using entity
????????? references.</font></p>
??????? ]]>
????? </description>
????? <Point>
??????? <coordinates>102.595626,14.996729</coordinates>
????? </Point>
??? </Placemark>
?</Document>
</kml>
3 疊層
疊層是覆蓋在地球表面的圖像。一個簡單的疊層KML代碼如下所示：
<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://earth.google.com/kml/2.1">
<Folder>???
<name>Ground Overlays</name>???
<description>Examples of ground overlays</description>???
<GroundOverlay>?????
<name>Large-scale overlay on terrain</name>?????
<description>Overlay shows Mount Etna erupting on July 13th, 2001.</description>
<Icon>???????
<href>http://code.google.com/apis/kml/documentation/etna.jpg</href>?????
</Icon>?????
<LatLonBox>???????
<north>37.91904192681665</north>???????
<south>37.46543388598137</south>???????
<east>15.35832653742206</east>???????
<west>14.60128369746704</west>???????
<rotation>-0.1556640799496235</rotation>?????
</LatLonBox>???
</GroundOverlay>?
</Folder>
</kml>
在<GroundOverlay>中，它包含兩個較新的標記：
<Icon>：指定圖片的URL；
<LatLonBox>：指定圖片的位置和范圍。
Google Earth支持JPEG，BMP， GIF， TIFF， TGA和PNG等格式的圖像。
4 路線
在KML里面，路線由<LineString>元素來創(chuàng)建。如下所示：
<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://earth.google.com/kml/2.1">
<Document>???
<name>Paths</name>
<description>Examples of paths. Note that the tessellate tag is by default????? set to 0. If you want to create tessellated lines, they must be authored????? (or edited) directly in KML.</description>
<Style id="yellowLineGreenPoly">?????
<LineStyle>???????
<color>7f00ffff</color>???????
<width>4</width>?????
</LineStyle>?????
<PolyStyle>???????
<color>7f00ff00</color>?????
</PolyStyle>???
</Style>
<Placemark>
<name>Absolute Extruded</name>?????
<description>Transparent green wall with yellow outlines</description>????? <styleUrl>#yellowLineGreenPoly</styleUrl>?????
<LineString>???????
<extrude>1</extrude>???????
<tessellate>1</tessellate>???????
<altitudeMode>absolute</altitudeMode>???????
<coordinates>
-112.2550785337791,36.07954952145647,2357?????????
-112.2549277039738,36.08117083492122,2357?????????
-112.2552505069063,36.08260761307279,2357?????????
-112.2564540158376,36.08395660588506,2357?????????
-112.2580238976449,36.08511401044813,2357?????????
-112.2595218489022,36.08584355239394,2357?????????
-112.2608216347552,36.08612634548589,2357?????????
-112.262073428656,36.08626019085147,2357?????????
-112.2633204928495,36.08621519860091,2357?????????
-112.2644963846444,36.08627897945274,2357?????????
-112.2656969554589,36.08649599090644,2357
</coordinates>?????
</LineString>
</Placemark>?
</Document>
</kml>
5 多邊形
多邊形由<Polygon>定義，包括<outerBoundaryIs>和<innerBoundaryIs>，如下所示：
<?xml version="1.0" encoding="UTF-8"?><kml xmlns="http://earth.google.com/kml/2.1">
<Placemark>???
<name>The Pentagon</name>???
<Polygon>?????
<extrude>1</extrude>?????
<altitudeMode>relativeToGround</altitudeMode>?????
<outerBoundaryIs>???????
<LinearRing>?????????
<coordinates>???????????
-77.05788457660967,38.87253259892824,100????????????
-77.05465973756702,38.87291016281703,100????????????
-77.05315536854791,38.87053267794386,100????????????
-77.05552622493516,38.868757801256,100????????????
-77.05844056290393,38.86996206506943,100????????????
-77.05788457660967,38.87253259892824,100?????????
</coordinates>???????
</LinearRing>?????
</outerBoundaryIs>?????
<innerBoundaryIs> ???????
<LinearRing>?????????
<coordinates>???????????
-77.05668055019126,38.87154239798456,100????????????
-77.05542625960818,38.87167890344077,100????????????
-77.05485125901024,38.87076535397792,100????????????
-77.05577677433152,38.87008686581446,100????????????
-77.05691162017543,38.87054446963351,100????????????
-77.05668055019126,38.87154239798456,100?????????
</coordinates>???????
</LinearRing>?????
</innerBoundaryIs>???
</Polygon>?
</Placemark>
</kml>
