1.使用Android進行地理編碼
若是打算使用地圖作一些實際的事情,可能必須將地址(或位置)轉換爲緯度/經度對。此概念稱爲地理編碼,android.location.Geocoder 類提供了此功能。實際上,Geocoder既提供了前向轉換,也提供了後向轉換--------它能夠獲取地址並返回經度/緯度,也能夠將經度/緯度對轉換爲一組地址。該類提供瞭如下方法。
- List<Address> getFromLocation(double latitude,double longitude,int maxResults);
- List<Address> getFromLocationName(String locationName, int maxResults, double lowerLeftLatitude, double lowerLeftLongitue, double upperRightLatitude, double upperRightLongitude);
- List<Address> getFromLocationName(String locationName, int maxResults)。
List<Address> getFromLocation(double latitude,double longitude,int maxResults); List<Address> getFromLocationName(String locationName, int maxResults, double lowerLeftLatitude, double lowerLeftLongitue, double upperRightLatitude, double upperRightLongitude); List<Address> getFromLocationName(String locationName, int maxResults)。
List<Address> getFromLocation(double latitude,double longitude,int maxResults); List<Address> getFromLocationName(String locationName, int maxResults, double lowerLeftLatitude, double lowerLeftLongitue, double upperRightLatitude, double upperRightLongitude); List<Address> getFromLocationName(String locationName, int maxResults)。
事實證實,計算地址並不徹底屬於科學範疇,由於能夠經過各類方式來描述位置。例如,getFromLocationName() 方法能夠得到地方的名稱、物理地址和機場編號,或者該位置的流行名稱。所以,這些方法提供了一個地址列表,而不是一個地址。由於這些方法返回一個列表,因此最好提供1~5的maxResults 值來限制結果集,下面咱們來看一個查詢地址的例子,和原來同樣咱們得本身定義一個類來繼承MapActivity,先來看看運行效果。
咱們的佈局文件
- <?xml version="1.0" encoding="utf-8"?>
- <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:orientation="vertical"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- >
- <LinearLayout android:layout_width="fill_parent"
- android:layout_alignParentBottom="true"
- android:layout_height="wrap_content" android:orientation="vertical">
- <EditText
- android:id="@+id/location"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:text="請輸入地址..."/>
- <Button
- android:id="@+id/geocodeBtn"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="Find Location" />
- </LinearLayout>
- <com.google.android.maps.MapView
- android:id="@+id/geoMap"
- android:clickable="true"
- android:layout_width="fill_parent"
- android:layout_height="320px"
- android:apiKey="0XemFEdFemEDqY3dE3Ko9ELJX12MRLjJGKEJ01g"
- />
- </RelativeLayout>
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <LinearLayout android:layout_width="fill_parent" android:layout_alignParentBottom="true" android:layout_height="wrap_content" android:orientation="vertical"> <EditText android:id="@+id/location" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="請輸入地址..."/> <Button android:id="@+id/geocodeBtn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Find Location" /> </LinearLayout> <com.google.android.maps.MapView android:id="@+id/geoMap" android:clickable="true" android:layout_width="fill_parent" android:layout_height="320px" android:apiKey="0XemFEdFemEDqY3dE3Ko9ELJX12MRLjJGKEJ01g" /> </RelativeLayout>
AndroidManifest.xml文件
- <?xml version="1.0" encoding="utf-8"?>
- <manifest xmlns:android="http://schemas.android.com/apk/res/android"
- package="xiaohang.zhimeng" android:versionCode="1" android:versionName="1.0">
- <uses-sdk android:minSdkVersion="10" />
- <application android:icon="@drawable/icon" android:label="@string/app_name">
- <uses-library android:name="com.google.android.maps" />
- <activity android:name=".MainActivity" android:label="@string/app_name">
- <intent-filter>
- <action android:name="android.intent.action.MAIN" />
- <category android:name="android.intent.category.LAUNCHER" />
- </intent-filter>
- </activity>
- </application>
- <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
- <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
- <uses-permission android:name="android.permission.INTERNET" />
- </manifest>
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="xiaohang.zhimeng" android:versionCode="1" android:versionName="1.0"> <uses-sdk android:minSdkVersion="10" /> <application android:icon="@drawable/icon" android:label="@string/app_name"> <uses-library android:name="com.google.android.maps" /> <activity android:name=".MainActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.INTERNET" /> </manifest>
咱們的MainActivity類
- package xiaohang.zhimeng;
- import java.util.List;
- import com.google.android.maps.GeoPoint;
- import com.google.android.maps.MapActivity;
- import com.google.android.maps.MapView;
- import android.location.Address;
- import android.location.Geocoder;
- import android.os.Bundle;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.EditText;
- public class MainActivity extends MapActivity {
- Geocoder geocoder = null;
- MapView mapView = null;
- @Override
- protected boolean isLocationDisplayed() {
- return false;
- }
- @Override
- protected boolean isRouteDisplayed() {
- return false;
- }
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- mapView = (MapView) findViewById(R.id.geoMap);
- mapView.setBuiltInZoomControls(true);
- // 經度:116.3946533203125
- // 緯度:39.87601941962116
- int lat = (int) (39.87601941962116 * 1E6);
- int lng = (int) (116.3946533203125 * 1E6);
- GeoPoint pt = new GeoPoint(lat, lng);
- mapView.getController().setZoom(10);
- mapView.getController().setCenter(pt);
- Button geoBtn = (Button) findViewById(R.id.geocodeBtn);
- geocoder = new Geocoder(this);
- geoBtn.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- try {
- EditText loc = (EditText) findViewById(R.id.location);
- String locationName = loc.getText().toString();
- List<Address> addressList = geocoder.getFromLocationName(
- locationName, 5);
- if (addressList != null && addressList.size() > ) {
- int lat = (int) (addressList.get().getLatitude() * 1E6);
- int lng = (int) (addressList.get().getLongitude() * 1E6);
- GeoPoint pt = new GeoPoint(lat, lng);
- mapView.getController().setZoom(15);
- mapView.getController().setCenter(pt);
- }
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- });
- }
- }
package xiaohang.zhimeng; import java.util.List; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapView; import android.location.Address; import android.location.Geocoder; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; public class MainActivity extends MapActivity { Geocoder geocoder = null; MapView mapView = null; @Override protected boolean isLocationDisplayed() { return false; } @Override protected boolean isRouteDisplayed() { return false; } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mapView = (MapView) findViewById(R.id.geoMap); mapView.setBuiltInZoomControls(true); // 經度:116.3946533203125 // 緯度:39.87601941962116 int lat = (int) (39.87601941962116 * 1E6); int lng = (int) (116.3946533203125 * 1E6); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(10); mapView.getController().setCenter(pt); Button geoBtn = (Button) findViewById(R.id.geocodeBtn); geocoder = new Geocoder(this); geoBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { try { EditText loc = (EditText) findViewById(R.id.location); String locationName = loc.getText().toString(); List<Address> addressList = geocoder.getFromLocationName( locationName, 5); if (addressList != null && addressList.size() > 0) { int lat = (int) (addressList.get(0).getLatitude() * 1E6); int lng = (int) (addressList.get(0).getLongitude() * 1E6); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(15); mapView.getController().setCenter(pt); } } catch (Exception e) { e.printStackTrace(); } } }); } }
package xiaohang.zhimeng; import java.util.List; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapView; import android.location.Address; import android.location.Geocoder; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; public class MainActivity extends MapActivity { Geocoder geocoder = null; MapView mapView = null; @Override protected boolean isLocationDisplayed() { return false; } @Override protected boolean isRouteDisplayed() { return false; } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mapView = (MapView) findViewById(R.id.geoMap); mapView.setBuiltInZoomControls(true); // 經度:116.3946533203125 // 緯度:39.87601941962116 int lat = (int) (39.87601941962116 * 1E6); int lng = (int) (116.3946533203125 * 1E6); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(10); mapView.getController().setCenter(pt); Button geoBtn = (Button) findViewById(R.id.geocodeBtn); geocoder = new Geocoder(this); geoBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { try { EditText loc = (EditText) findViewById(R.id.location); String locationName = loc.getText().toString(); List<Address> addressList = geocoder.getFromLocationName( locationName, 5); if (addressList != null && addressList.size() > 0) { int lat = (int) (addressList.get(0).getLatitude() * 1E6); int lng = (int) (addressList.get(0).getLongitude() * 1E6); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(15); mapView.getController().setCenter(pt); } } catch (Exception e) { e.printStackTrace(); } } }); } }
可是若是這個類要是這麼寫,就會有問題了。可是感受這麼寫是沒錯誤的,可是每當你點擊一次Find Location按鈕就會出現一次異常(IOException),異常見下圖。
說什麼服務不能夠用,去網上一搜 碰見這問題的人還真很多,eoe上邊也有 可是沒說怎麼解決,不了了之了。至於爲何有這個異常,我也不能準確的告訴你們 我也不太清楚,網上說什麼的都有。 什麼 是bug之類的 等等,你們能夠去網上搜搜 最後本身這樣寫一次試試。可是解決方法仍是有的,在這裏 http://code.google.com/p/android/issues/detail?id=8816 老外搞出來的方法,他們討論的也很火熱,感受比咱們 積極不少。你們看 21樓就好了, 呵呵。
具體解決方法就是本身定義了兩個靜態方法,我把這兩個方法放到了MapUtility類中,這個類是我本身定義的。
MapUtility類
- package xiaohang.zhimeng.tool;
- import java.io.IOException;
- import java.io.InputStream;
- import org.apache.http.HttpEntity;
- import org.apache.http.HttpResponse;
- import org.apache.http.client.ClientProtocolException;
- import org.apache.http.client.HttpClient;
- import org.apache.http.client.methods.HttpGet;
- import org.apache.http.impl.client.DefaultHttpClient;
- import org.json.JSONArray;
- import org.json.JSONException;
- import org.json.JSONObject;
- import com.google.android.maps.GeoPoint;
- public class MapUtility {
- public static JSONObject getLocationInfo(String address) {
- HttpGet httpGet = new HttpGet("http://maps.google."
- + "com/maps/api/geocode/json?address=" + address
- + "ka&sensor=false");
- HttpClient client = new DefaultHttpClient();
- HttpResponse response;
- StringBuilder stringBuilder = new StringBuilder();
- try {
- response = client.execute(httpGet);
- HttpEntity entity = response.getEntity();
- InputStream stream = entity.getContent();
- int b;
- while ((b = stream.read()) != -1) {
- stringBuilder.append((char) b);
- }
- } catch (ClientProtocolException e) {
- } catch (IOException e) {
- }
- JSONObject jsonObject = new JSONObject();
- try {
- jsonObject = new JSONObject(stringBuilder.toString());
- } catch (JSONException e) {
- e.printStackTrace();
- }
- return jsonObject;
- }
- // After executing this, another method converts that JSONObject into a
- // GeoPoint.
- public static GeoPoint getGeoPoint(JSONObject jsonObject) {
- Double lon = new Double();
- Double lat = new Double();
- try {
- lon = ((JSONArray) jsonObject.get("results")).getJSONObject()
- .getJSONObject("geometry").getJSONObject("location")
- .getDouble("lng");
- lat = ((JSONArray) jsonObject.get("results")).getJSONObject()
- .getJSONObject("geometry").getJSONObject("location")
- .getDouble("lat");
- } catch (JSONException e) {
- e.printStackTrace();
- }
- return new GeoPoint((int) (lat * 1E6), (int) (lon * 1E6));
- }
- }
package xiaohang.zhimeng.tool; import java.io.IOException; import java.io.InputStream; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.google.android.maps.GeoPoint; public class MapUtility { public static JSONObject getLocationInfo(String address) { HttpGet httpGet = new HttpGet("http://maps.google." + "com/maps/api/geocode/json?address=" + address + "ka&sensor=false"); HttpClient client = new DefaultHttpClient(); HttpResponse response; StringBuilder stringBuilder = new StringBuilder(); try { response = client.execute(httpGet); HttpEntity entity = response.getEntity(); InputStream stream = entity.getContent(); int b; while ((b = stream.read()) != -1) { stringBuilder.append((char) b); } } catch (ClientProtocolException e) { } catch (IOException e) { } JSONObject jsonObject = new JSONObject(); try { jsonObject = new JSONObject(stringBuilder.toString()); } catch (JSONException e) { e.printStackTrace(); } return jsonObject; } // After executing this, another method converts that JSONObject into a // GeoPoint. public static GeoPoint getGeoPoint(JSONObject jsonObject) { Double lon = new Double(0); Double lat = new Double(0); try { lon = ((JSONArray) jsonObject.get("results")).getJSONObject(0) .getJSONObject("geometry").getJSONObject("location") .getDouble("lng"); lat = ((JSONArray) jsonObject.get("results")).getJSONObject(0) .getJSONObject("geometry").getJSONObject("location") .getDouble("lat"); } catch (JSONException e) { e.printStackTrace(); } return new GeoPoint((int) (lat * 1E6), (int) (lon * 1E6)); } }
package xiaohang.zhimeng.tool; import java.io.IOException; import java.io.InputStream; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.google.android.maps.GeoPoint; public class MapUtility { public static JSONObject getLocationInfo(String address) { HttpGet httpGet = new HttpGet("http://maps.google." + "com/maps/api/geocode/json?address=" + address + "ka&sensor=false"); HttpClient client = new DefaultHttpClient(); HttpResponse response; StringBuilder stringBuilder = new StringBuilder(); try { response = client.execute(httpGet); HttpEntity entity = response.getEntity(); InputStream stream = entity.getContent(); int b; while ((b = stream.read()) != -1) { stringBuilder.append((char) b); } } catch (ClientProtocolException e) { } catch (IOException e) { } JSONObject jsonObject = new JSONObject(); try { jsonObject = new JSONObject(stringBuilder.toString()); } catch (JSONException e) { e.printStackTrace(); } return jsonObject; } // After executing this, another method converts that JSONObject into a // GeoPoint. public static GeoPoint getGeoPoint(JSONObject jsonObject) { Double lon = new Double(0); Double lat = new Double(0); try { lon = ((JSONArray) jsonObject.get("results")).getJSONObject(0) .getJSONObject("geometry").getJSONObject("location") .getDouble("lng"); lat = ((JSONArray) jsonObject.get("results")).getJSONObject(0) .getJSONObject("geometry").getJSONObject("location") .getDouble("lat"); } catch (JSONException e) { e.printStackTrace(); } return new GeoPoint((int) (lat * 1E6), (int) (lon * 1E6)); } }
這兩個方法就很少解釋了,反正咱們最終的目的是須要一個GeoPoint對象,它給咱們返回正確的GeoPoint對象就好了,你們能夠去原地址去看看他們怎麼討論了,連接在上邊我已經貼出來了,如今咱們在搜索tian an men 就會把tian an men給咱們顯示在地圖的中央了,沒修改以前是 一點 一次異常,如今的效果以下圖,( 你們知道 tian an men是啥意思吧,自動eye被 oracle搞過一次 法律意識愈來愈強啊。。。。 )
要體驗地理編碼在Android中的使用,能夠在 EditText字段中鍵入位置名稱或它的地址,而後點擊 Find Location按鈕。要找到某個位置的地址,調用 Geocoder的 getFromLocationName()方法。位置能夠是地址或流行名稱,好比 「故宮」。地理編碼是一項實時操做,因此根據Android文檔的建議,咱們建議將結果限制爲5個。對getFromLocationName()的調用返回一個地址列表。示例程序獲取該地址列表並處理第一個地址(若是存在)。每一個地址都具備經緯度。可使用它來建立 GeoPoint。而後調用地圖控制器並導航到該點。縮放級別能夠設置爲1~21 (包括1和21)的整數。在從1向21移動時,縮放級別每次將增長兩級。
對於地理編碼,應該瞭解幾點。第一,返回的地址並不老是準確的地址。顯然,因爲返回的地址列表取決於輸入的準確度,因此須要儘可能向 Geocoder 提供準確的位置名稱。第二,儘可能將 maxResults 設置爲1~5的值。最後,應該認真考慮在不一樣於UI線程的線程中執行地理編碼操做。這有兩個緣由。第一個很明顯:這項操做很耗時,並且你必定不但願UI在進行地理編碼時停頓,若是停頓會阻塞整個用戶界面。當在執行一些耗時的操做的時候,不能及時地分發 事件,包括用戶界面重繪事件。從用戶的角度來看,應用程序看上去像掛掉了。更糟糕的是,若是阻塞應用程序的時間過長(5秒鐘)Android會向用戶提示 一些信息,即打開一個「應用程序沒有相應(application not responding)」ANR 的對話框,關於線程的更多內容請你們看這裏 http://byandby.iteye.com/blog/825071 第二個緣由是,對於移動設備,始終須要假設網絡鏈接可能丟失而且鏈接很弱。所以,須要恰當地處理I/O 異常和超時。計算出地址之後,就能夠將結果發送給UI線程,下面咱們看看使用後臺線程進行地理編碼,這個例子和上一個例子同樣 惟一不一樣的就是 這個例子把查詢地址的操做放到 另一個輔助線程裏來執行了,上一個是全部的操做都在UI線程裏,下面是咱們的Activity類,GeocodingDemoActivity,咱們看看怎麼實現。。。
GeocodingDemoActivity類
- package xiaohang.zhimeng;
- import java.util.List;
- import org.json.JSONObject;
- import xiaohang.zhimeng.tools.MapUtility;
- import android.app.AlertDialog;
- import android.app.Dialog;
- import android.app.ProgressDialog;
- import android.location.Address;
- import android.location.Geocoder;
- import android.os.Bundle;
- import android.os.Handler;
- import android.os.Message;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.EditText;
- import com.google.android.maps.GeoPoint;
- import com.google.android.maps.MapActivity;
- import com.google.android.maps.MapView;
- public class GeocodingDemoActivity extends MapActivity {
- Geocoder geocoder = null;
- MapView mapView = null;
- ProgressDialog progDialog = null;
- List<Address> addressList = null;
- @Override
- protected boolean isLocationDisplayed() {
- return false;
- }
- @Override
- protected boolean isRouteDisplayed() {
- return false;
- }
- @Override
- protected void onCreate(Bundle icicle) {
- super.onCreate(icicle);
- setContentView(R.layout.main);
- mapView = (MapView) findViewById(R.id.geoMap);
- mapView.setBuiltInZoomControls(true);
- // 北京經緯度
- // 經度:116.3946533203125
- // 緯度:39.87601941962116
- int lat = (int) (39.87601941962116 * 1000000);
- int lng = (int) (116.3946533203125 * 1000000);
- GeoPoint pt = new GeoPoint(lat, lng);
- mapView.getController().setZoom(10);
- mapView.getController().setCenter(pt);
- Button geoBtn = (Button) findViewById(R.id.geocodeBtn);
- geoBtn.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- EditText loc = (EditText) findViewById(R.id.location);
- String locationName = loc.getText().toString();
- progDialog = ProgressDialog.show(GeocodingDemoActivity.this,
- "Processing.....", "Finding Location", true, false);
- findLocation(locationName);
- }
- });
- }
- private void findLocation(final String locationName) {
- Thread thrd = new Thread() {
- @Override
- public void run() {
- System.out.println("線程Name是:"
- + Thread.currentThread().getName());
- try {
- // do backgrond work
- JSONObject jo = MapUtility.getLocationInfo(locationName);
- GeoPoint gp = MapUtility.getGeoPoint(jo);
- Message message = uiCallback.obtainMessage();
- message.obj = gp;
- message.sendToTarget();
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- };
- thrd.start();
- }
- // ui thread callback handler
- private Handler uiCallback = new Handler() {
- public void handleMessage(android.os.Message msg) {
- System.out.println("線程Name是:" + Thread.currentThread().getName());
- progDialog.dismiss();
- GeoPoint pt = (GeoPoint) msg.obj;
- if (pt != null) {
- mapView.getController().setZoom(15);
- mapView.getController().setCenter(pt);
- } else {
- Dialog foundNothingDlg = new AlertDialog.Builder(
- GeocodingDemoActivity.this).setIcon()
- .setTitle("Failed to Find Location")
- .setPositiveButton("OK", null)
- .setMessage("Location Not Found").create();
- foundNothingDlg.show();
- }
- };
- };
- }
package xiaohang.zhimeng; import java.util.List; import org.json.JSONObject; import xiaohang.zhimeng.tools.MapUtility; import android.app.AlertDialog; import android.app.Dialog; import android.app.ProgressDialog; import android.location.Address; import android.location.Geocoder; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapView; public class GeocodingDemoActivity extends MapActivity { Geocoder geocoder = null; MapView mapView = null; ProgressDialog progDialog = null; List<Address> addressList = null; @Override protected boolean isLocationDisplayed() { return false; } @Override protected boolean isRouteDisplayed() { return false; } @Override protected void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); mapView = (MapView) findViewById(R.id.geoMap); mapView.setBuiltInZoomControls(true); // 北京經緯度 // 經度:116.3946533203125 // 緯度:39.87601941962116 int lat = (int) (39.87601941962116 * 1000000); int lng = (int) (116.3946533203125 * 1000000); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(10); mapView.getController().setCenter(pt); Button geoBtn = (Button) findViewById(R.id.geocodeBtn); geoBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { EditText loc = (EditText) findViewById(R.id.location); String locationName = loc.getText().toString(); progDialog = ProgressDialog.show(GeocodingDemoActivity.this, "Processing.....", "Finding Location", true, false); findLocation(locationName); } }); } private void findLocation(final String locationName) { Thread thrd = new Thread() { @Override public void run() { System.out.println("線程Name是:" + Thread.currentThread().getName()); try { // do backgrond work JSONObject jo = MapUtility.getLocationInfo(locationName); GeoPoint gp = MapUtility.getGeoPoint(jo); Message message = uiCallback.obtainMessage(); message.obj = gp; message.sendToTarget(); } catch (Exception e) { e.printStackTrace(); } } }; thrd.start(); } // ui thread callback handler private Handler uiCallback = new Handler() { public void handleMessage(android.os.Message msg) { System.out.println("線程Name是:" + Thread.currentThread().getName()); progDialog.dismiss(); GeoPoint pt = (GeoPoint) msg.obj; if (pt != null) { mapView.getController().setZoom(15); mapView.getController().setCenter(pt); } else { Dialog foundNothingDlg = new AlertDialog.Builder( GeocodingDemoActivity.this).setIcon(0) .setTitle("Failed to Find Location") .setPositiveButton("OK", null) .setMessage("Location Not Found").create(); foundNothingDlg.show(); } }; }; }
package xiaohang.zhimeng; import java.util.List; import org.json.JSONObject; import xiaohang.zhimeng.tools.MapUtility; import android.app.AlertDialog; import android.app.Dialog; import android.app.ProgressDialog; import android.location.Address; import android.location.Geocoder; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapView; public class GeocodingDemoActivity extends MapActivity { Geocoder geocoder = null; MapView mapView = null; ProgressDialog progDialog = null; List<Address> addressList = null; @Override protected boolean isLocationDisplayed() { return false; } @Override protected boolean isRouteDisplayed() { return false; } @Override protected void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); mapView = (MapView) findViewById(R.id.geoMap); mapView.setBuiltInZoomControls(true); // 北京經緯度 // 經度:116.3946533203125 // 緯度:39.87601941962116 int lat = (int) (39.87601941962116 * 1000000); int lng = (int) (116.3946533203125 * 1000000); GeoPoint pt = new GeoPoint(lat, lng); mapView.getController().setZoom(10); mapView.getController().setCenter(pt); Button geoBtn = (Button) findViewById(R.id.geocodeBtn); geoBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { EditText loc = (EditText) findViewById(R.id.location); String locationName = loc.getText().toString(); progDialog = ProgressDialog.show(GeocodingDemoActivity.this, "Processing.....", "Finding Location", true, false); findLocation(locationName); } }); } private void findLocation(final String locationName) { Thread thrd = new Thread() { @Override public void run() { System.out.println("線程Name是:" + Thread.currentThread().getName()); try { // do backgrond work JSONObject jo = MapUtility.getLocationInfo(locationName); GeoPoint gp = MapUtility.getGeoPoint(jo); Message message = uiCallback.obtainMessage(); message.obj = gp; message.sendToTarget(); } catch (Exception e) { e.printStackTrace(); } } }; thrd.start(); } // ui thread callback handler private Handler uiCallback = new Handler() { public void handleMessage(android.os.Message msg) { System.out.println("線程Name是:" + Thread.currentThread().getName()); progDialog.dismiss(); GeoPoint pt = (GeoPoint) msg.obj; if (pt != null) { mapView.getController().setZoom(15); mapView.getController().setCenter(pt); } else { Dialog foundNothingDlg = new AlertDialog.Builder( GeocodingDemoActivity.this).setIcon(0) .setTitle("Failed to Find Location") .setPositiveButton("OK", null) .setMessage("Location Not Found").create(); foundNothingDlg.show(); } }; }; }
此次咱們再來看看運行效果。
從下圖咱們能看出 查詢操做在不一樣的線程中完成。
最後在提醒你們若是下載源碼 注意替換成本身的 密鑰。