在google地图上画出两个地点的行走路线

Google Direction API提供了更丰富的路线信息数据。由于访问量过大吧，谷歌现在不提供了查询路线的接口API，现在要想获得一个路线我们可以通过URL访问google然后解析得到的KML文件，得到路线的每个点的经纬度，然互在一个图层上画出这些点。代码来自于对一些网上资源的整理，一共提供了连个方法，一个通过两个地方的名字，一个是通过两个地点的经纬度，但是有时候会出现错误的别是对中国的城市，还有就是别用中文，要不会很惨，希望有人给出一个更好的方法

[图片] 未命名1.jpg

[代码] 新建一个图层

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package com.android.antkingwei.google.direction; 

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import android.graphics.Canvas; 

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import android.graphics.Color; 

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import android.graphics.Paint; 

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import android.graphics.Point; 

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import com.google.android.maps.GeoPoint; 

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import com.google.android.maps.MapView; 

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import com.google.android.maps.Overlay; 

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import com.google.android.maps.Projection; 

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public class DirectionPathOverlay extends Overlay { 

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private GeoPoint gp1; 

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private GeoPoint gp2; 

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public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) { 

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this.gp1 = gp1; 

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this.gp2 = gp2; 

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} 

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@Override

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public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) { 

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Projection projection = mapView.getProjection(); 

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if(shadow == false) { 

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Paint paint = new Paint(); 

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paint.setAntiAlias(true); 

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Point point = new Point(); 

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projection.toPixels(gp1, point); 

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paint.setColor(Color.BLUE); 

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Point point2 = new Point(); 

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projection.toPixels(gp2, point2); 

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paint.setStrokeWidth(2); 

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canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint); 

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} 

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return super.draw(canvas, mapView, shadow, when); 

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} 

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@Override

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public void draw(Canvas canvas, MapView mapView, boolean shadow) { 

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super.draw(canvas, mapView, shadow); 

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} 

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}

[代码] 主类

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package com.android.antkingwei.google.direction; 

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import java.net.HttpURLConnection; 

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import java.net.URL; 

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import javax.xml.parsers.DocumentBuilder; 

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import javax.xml.parsers.DocumentBuilderFactory; 

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import org.w3c.dom.Document; 

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import org.w3c.dom.Node; 

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import org.w3c.dom.NodeList; 

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import com.google.android.maps.GeoPoint; 

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import com.google.android.maps.MapActivity; 

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import com.google.android.maps.MapController; 

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import com.google.android.maps.MapView; 

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import android.app.Activity; 

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import android.os.Bundle; 

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import android.util.Log; 

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public class MainActivity extends MapActivity { 

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private MapView myMapView; 

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private GeoPoint geoPoint; 

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private MapController myMC; 

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private String[] pairs; 

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/** Called when the activity is first created. */

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@Override

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public void onCreate(Bundle savedInstanceState) { 

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super.onCreate(savedInstanceState); 

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setContentView(R.layout.main); 

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myMapView = (MapView) findViewById(R.id.mapview); 

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geoPoint = null; 

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myMapView.setSatellite(false); 

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//通过地名 

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//pairs = getDirectionData("ahmedabad", "vadodara"); 

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//通过四个坐标 

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pairs = getUrl(22.5348,113.97246,35.422006,119.524095); 

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String[] lngLat = pairs[0].split(","); 

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// STARTING POINT 

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GeoPoint startGP = new GeoPoint((int)(Double.parseDouble(lngLat[1]) * 1E6), (int) (Double.parseDouble(lngLat[0]) * 1E6)); 

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myMC = myMapView.getController(); 

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geoPoint = startGP; 

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myMC.setCenter(geoPoint); 

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myMC.setZoom(8); 

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myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP)); 

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// NAVIGATE THE PATH 

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GeoPoint gp1; 

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GeoPoint gp2 = startGP; 

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for (int i = 1; i < pairs.length; i++) { 

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lngLat = pairs[i].split(","); 

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gp1 = gp2; 

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// watch out! For GeoPoint, first:latitude, second:longitude 

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gp2 = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6),(int) (Double.parseDouble(lngLat[0]) * 1E6)); 

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myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2)); 

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Log.d("xxx", "pair:" + pairs[i]); 

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} 

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// END POINT 

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myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2)); 

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myMapView.getController().animateTo(startGP); 

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myMapView.setBuiltInZoomControls(true); 

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myMapView.displayZoomControls(true); 

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} 

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@Override

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protected boolean isRouteDisplayed() { 

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// TODO Auto-generated method stub 

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return false; 

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} 

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/** 

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* 通过四个坐标点，获得KML然后通过DOM解析 

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* @param fromLat 

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* @param fromLon 

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* @param toLat 

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* @param toLon 

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* @return 

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*/

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public String[] getUrl(double fromLat,double fromLon,double toLat,double toLon){ 

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String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="+fromLat+","+fromLon+"&daddr="+toLat+","+toLon+"&ie=UTF8&0&om=0&output=kml"; 

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Log.d("URL", urlString); 

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Document doc = null; 

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HttpURLConnection urlConnection = null; 

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URL url = null; 

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String pathConent = ""; 

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try{ 

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url = new URL(urlString.toString()); 

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urlConnection = (HttpURLConnection) url.openConnection(); 

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urlConnection.setRequestMethod("GET"); 

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urlConnection.setDoOutput(true); 

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urlConnection.setDoInput(true); 

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urlConnection.connect(); 

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DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 

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DocumentBuilder db = dbf.newDocumentBuilder(); 

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doc = db.parse(urlConnection.getInputStream()); 

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} catch (Exception e){} 

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NodeList nl = doc.getElementsByTagName("LineString"); 

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for(int s=0; s< nl.getLength(); s++){ 

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Node rootNode = nl.item(s); 

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NodeList configItems = rootNode.getChildNodes(); 

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for(int x=0; x < configItems.getLength(); x++) { 

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Node lineStringNode = configItems.item(x); 

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NodeList path = lineStringNode.getChildNodes(); 

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pathConent = path.item(0).getNodeValue(); 

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} 

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} 

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String[] tempContent = pathConent.split(" "); 

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return tempContent; 

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} 

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/** 

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* 通过连个地名获得KML然后进行DOM解析 

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* @param srcPlace 

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* @param destPlace 

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* @return 

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*/

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private String[] getDirectionData(String srcPlace, String destPlace) { 

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String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="+srcPlace+"&daddr="+destPlace+"&ie=UTF&om=0&output=kml"; 

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Log.d("URL", urlString); 

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Document doc = null; 

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HttpURLConnection urlConnection = null; 

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URL url = null; 

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String pathConent = ""; 

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try{ 

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url = new URL(urlString.toString()); 

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urlConnection = (HttpURLConnection) url.openConnection(); 

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urlConnection.setRequestMethod("GET"); 

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urlConnection.setDoOutput(true); 

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urlConnection.setDoInput(true); 

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urlConnection.connect(); 

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DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 

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DocumentBuilder db = dbf.newDocumentBuilder(); 

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doc = db.parse(urlConnection.getInputStream()); 

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} catch (Exception e){} 

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NodeList nl = doc.getElementsByTagName("LineString"); 

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for(int s=0; s< nl.getLength(); s++){ 

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Node rootNode = nl.item(s); 

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NodeList configItems = rootNode.getChildNodes(); 

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for(int x=0; x < configItems.getLength(); x++) { 

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Node lineStringNode = configItems.item(x); 

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NodeList path = lineStringNode.getChildNodes(); 

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pathConent = path.item(0).getNodeValue(); 

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} 

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} 

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String[] tempContent = pathConent.split(" "); 

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return tempContent; 

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} 

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}

[代码] main.xml

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<?xml version="1.0" encoding="utf-8"?> 

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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

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android:orientation="vertical"

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android:layout_width="fill_parent"

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android:layout_height="fill_parent"

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> 

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<TextView 

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android:layout_width="fill_parent" 

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android:layout_height="wrap_content" 

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android:text="@string/hello"

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/> 

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<com.google.android.maps.MapView

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xmlns:android="http://schemas.android.com/apk/res/android"

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android:id="@+id/mapview"

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android:layout_width="fill_parent"

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android:layout_height="fill_parent"

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android:enabled="true"

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android:clickable="true"

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android:apiKey="0FZLYf-YM4SRrJrJum55MeeaO4Gd_IitVFmtUeA"/> 

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</LinearLayout>

[代码] AndroidManifest.xml

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<?xml version="1.0" encoding="utf-8"?> 

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<manifest xmlns:android="http://schemas.android.com/apk/res/android"

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package="com.android.antkingwei.google.direction"

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android:versionCode="1"

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android:versionName="1.0"> 

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<uses-sdk android:minSdkVersion="7" /> 

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<application android:icon="@drawable/icon" android:label="@string/app_name"> 

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<activity android:name=".MainActivity"

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android:label="@string/app_name"> 

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<intent-filter> 

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<action android:name="android.intent.action.MAIN" /> 

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<category android:name="android.intent.category.LAUNCHER" /> 

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</intent-filter> 

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</activity> 

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<uses-library android:name="com.google.android.maps" /> 

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</application> 

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<uses-permission android:name="android.permission.INTERNET"></uses-permission> 

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<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> 

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<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> 

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<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> 

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</manifest>