Android------beginner GPS Positioning

<span id="Label3"></p><p><p>GPS English is the abbreviation of Global Positioning System gps.</p></p><p><p>Android for GPS feature support specifically provides a locationmanager, location manager. All the services and objects related to GPS positioning will be generated by this Object.</p></p><p><p><br>Get Locationmanager instance:<br>Locationmanager lm = (locationmanager) Getsystemservice (context.location_service)</p></p><p><p></p></p><p><p>Three core api:locationmanager, locationprovider, location</p></p><p><p></p></p><p><p>Locationmanager provides the following methods:</p></p><p><p>Boolean Addgpsstatuslistener (gpsstatus.listener Listener): adds a listener that listens for GPs status;</p></p><p><p>void Addproximityalert (double latitude,double longitude,float radius,long expiration,pendingintent intent): adds a proximity warning;</p></p><p><p>List Getallproviders (): get all the Locationprovider lists;<br>String getbestprovider (criteria Criteria,boolean enabledonly): Returns the optimal Locationprovider object according to the established conditions;</p></p><p><p>Gpsstatus getgpsstatus (gpsstatus status): get GPS status;</p></p><p><p>Location Getlastknownlocation (String provider): Gets the last known location based on locationprovider;</p></p><p><p>Locationprovider getprovider (String name): gets Locationprovider by name;</p></p><p><p>List getproviders (criteria Criteria,boolean enabledonly): The names of all locationprovier that satisfy the conditions are obtained according to the conditions of establishment;<br>List getproviders (boolean enabledonly): gets all available locationprovider;<br>Boolean isproviderenabled (String provider): determines whether the locationprovider of the established name is available;</p></p><p><p>void Removegpsstatuslistener (gpsstatus.listener Listener): Delete GPS status listener;</p></p><p><p>void Removeproximityalert (pendingintent intent): deletes an approaching warning;</p></p><p><p>void Requestlocationupdates (String provider,long mintime,float mindistance,pendingintent intent): The location information is obtained periodically through the specified locationprovider, and the corresponding components are started by intent;</p></p><p><p>void Requestlocationupdates (String provider,long mintime,float mindistance,lcoationlistener listener): Obtains the location information periodically through the specified locationprovider, and triggers the listener corresponding trigger;</p></p><p><p></p></p><p><p>Locationprovider class</p></p><p><p>The abstract identification of the positioning component, through which the relevant information of positioning can be obtained;</p></p><p><p>The following common methods are available:</p></p><p><p>String getName (): Returns the name of the locationprovider;</p></p><p><p>int getaccuracy (): Returns the precision of the locationprovider;</p></p><p><p>int getpowerrequirement (): Returns the power requirement of the locationprovider;</p></p><p><p>Boolean hasmonetarycost (): returns whether the Locationprovider is charged or free;</p></p><p><p>Boolean meetscriteria: determines whether the locationprovider satisfies the criteria criteria;</p></p><p><p>Boolean Requirescell (): determines whether the Locationprovider needs to access the network base station;</p></p><p><p>Boolean Requiresnetword (): Determines whether the Locationprovider requires network data;</p></p><p><p>Boolean Requiresstatellite (): determine if the Locationprovider requires access to the Satellite's positioning system;</p></p><p><p>Boolean Supportsaltitude (): determines whether the Locationprovider supports height information;</p></p><p><p>Boolean supportsbearing (): determines whether the Locationprovider supports directional information;</p></p><p><p>Boolean Supportsspeed (): determines whether the Locationprovider supports speed information;</p></p><p><p><br>Locationlistener: position listener, monitor position change, Monitor device switch and status</p></p><p><p></p></p><p><p>Location class</p></p><p><p>An abstract class representing location information;</p></p><p><p>Provides the following methods to obtain location information:</p></p><p><p>Float getaccuracy (): Get the accuracy of positioning information;</p></p><p><p>Double Getaltitude (): Gets the height of the positioning information;</p></p><p><p>Float getbearing (): Gets the orientation of the positioning information;</p></p><p><p>Double Getlatitude (): Gets the longitude of the location information;</p></p><p><p>Double Getlongitude (): Gets the latitude of the location information;</p></p><p><p>String Getprovider (): Gets the Locationprovider that provides the location information;</p></p><p><p>Float GetSpeed (): Gets the speed of positioning information;</p></p><p><p>Boolean hasaccuracy (): determines whether the location information has longitude information;</p></p><p><p>Boolean Hasaltitude (): determines whether the location information has high information;</p></p><p><p>Boolean hasbearing (): determines whether the location information has direction information;</p></p><p><p>Boolean Hasspeed (): determines whether the location information has speed information;</p></p><p><p></p></p><p><p></p></p><p><p></p></p><p><p><br>Locationlistener: position listener, monitor position change, Monitor device switch and status</p></p><p><p></p></p><p><p>Steps:<br>1. Get the Locationmanager object for the system<br>2. Use Locationmanager to obtain positioning information by specifying locationprovider, which is represented by the location object<br>3. Get positioning information from the Location object</p></p><p><p></p></p><p><p></p></p><p><p>Here are a few examples:</p></p><p><p>1. Get all the available locationprovider:</p></p><p><p>Layout file:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code"><linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools " android:layout_width=" fill_parent " android:layout_height=" fill_parent " android:orientation= "vertical" android:paddingbottom= "@dimen/activity_vertical_margin" android: paddingleft= "@dimen/activity_horizontal_margin" android:paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools:context= " Com.example.allproviderstest.AllProvidersTest "> <textview android:layout_width=" fill_parent " android:layout_height= "wrap_content" android:text= "@string/providerlist"/> <listview android:id= "@+id/providers" android:layout_width= "fill_parent" android:layout_height= "fill_ Parent "> </ListView></LinearLayout></pre></pre><p><p><br></p></p><p><p>Activity:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code">public class Allproviderstest extends Activity {ListView providers; Locationmanager lm; @Overrideprotected void onCreate (Bundle Savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.activity_all_providers_test);p roviders = (ListView) Findviewbyid (r.id.providers); lm = ( Locationmanager) Getsystemservice (context.location_service); list<string> providernames = lm.getallproviders (); arrayadapter<string> adapter = new Arrayadapter<string> (this,android. r.layout.simple_list_item_1, providernames);p Roviders.setadapter (adapter);}}</pre></pre><p><p></p></p><p><p><br>All available Locationprovider in the simulator are Two:<br>Passive: represented by the Locationprovider.passive_provider constant<br>Gps: represented by the Locationprovider.gps_provider Constant. Represents the Locationprovider object for locating information via GPS</p></p><p><p>There is also a locationprovider called NETWORK, which is represented by the Locationprovider.network_provider constant,<br>Represents a Locationprovider object that obtains location information through a mobile communication Network.</p></p><p><p></p></p><p><p></p></p><p><p>2. Obtain the specified Locationprovider by name:</p></p><p><p></p></p><p><p>For example:</p></p><p><p>Get gps-based Locationprovider:<br>Locationprovider Locprovider = Lm.getprovider (locationmanager.gps_provider)</p></p><p><p></p></p><p><p>Get Locationprovider According to Criteria:</p></p><p><p></p></p><p><p></p></p><p><p>Layout file:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code"><linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools " android:layout_width=" fill_parent " android:layout_height=" fill_parent " android:orientation= "vertical" android:paddingbottom= "@dimen/activity_vertical_margin" android: paddingleft= "@dimen/activity_horizontal_margin" android:paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools:context= " Com.example.freeproviderstest.FreeProvidersTest "> <textview android:layout_width=" fill_parent " android:layout_height= "wrap_content" android:text= "@string/providerlist"/> <listview android:id= "@+id/providers" android:layout_width= "fill_parent" android:layout_height= "fill_ Parent "/></linearlayout></pre></pre><p><p><br></p></p><p><p>Activity:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code">public class Freeproviderstest extends Activity {ListView providers; Locationmanager lm; @Overrideprotected void onCreate (Bundle Savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.activity_free_providers_test);p roviders = (ListView) Findviewbyid (r.id.providers); lm = ( Locationmanager) Getsystemservice (context.location_service);//create A locationprovider filter criteria for the criteria CRI = new criteria ( )///setup requires Locationprovider to be free. Cri.setcostallowed (false);//setup requires Locationprovider to provide height information cri.setaltituderequired (true);// Setup requires Locationprovider to provide direction information cri.setbearingrequired (true);//gets the name of the Locationprovider for all compound conditions of the system list<string> Providernames = Lm.getproviders (cri, false); System.out.println (providernames.size ()); arrayadapter<string> adapter = new Arrayadapter<string> (this,android. r.layout.simple_list_item_1, Providernames);//use a ListView to display all available Locationproviderproviders.setadapter (adapter);}}</pre></pre><p><p><br></p></p><p><p></p></p><p><p>3.<br>Get Location Data:</p></p><p><p><br>Send GPS information via simulator:</p></p><p><p>After you start the emulator, you can send GPS location information in the emulator Control panel under Ddms.</p></p><p><p></p></p><p><p>Layout file:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code"><linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools " android:layout_width=" fill_parent " android:layout_height=" fill_parent " android:orientation= "vertical" android:paddingbottom= "@dimen/activity_vertical_margin" android: paddingleft= "@dimen/activity_horizontal_margin" android:paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools:context= " Com.example.locationtest.LocationTest "> <edittext android:id=" @+id/show " android:layout_ Width= "fill_parent" android:layout_height= "wrap_content" android:cursorvisible= "false" android: Editable= "false"/></linearlayout></pre></pre><p><p><br></p></p><p><p>Activity:</p></p><pre class="html" name="code">public class Locationtest extends Activity {//define Locationmanager object Locationmanager locmanager;// Defines the EditText component in the program interface EditText show; @Overrideprotected void onCreate (Bundle Savedinstancestate) {super.oncreate ( savedinstancestate); Setcontentview (r.layout.activity_location_test); show = (EditText) Findviewbyid (R.id.show); Locmanager = (locationmanager) Getsystemservice (context.location_service);//obtain Nearest nearest location information from GPS Locmanager.getlastknownlocation (locationmanager.gps_provider);//use Location According to the EditText display Updateview (location);// Set the GPS location information to get once every 3 seconds locmanager.requestlocationupdates (locationmanager.gps_provider, 3000,8, new Locationlistener ()// ①{@Overridepublic void onlocationchanged {//when GPS location information is changed, update location updateview;} @Overridepublic void onproviderdisabled (String provider) {updateview (null);} @Overridepublic void onproviderenabled (String provider) {//when The GPS Locationprovider is available, update the location Updateview ( Locmanager.getlastknownlocation (provider));} @Overridepublic void Onstatuschanged (String provider, int status,bundle Extras) {}});} Update EditText content that is displayed public void Updateview (location newlocation) {if (newlocation! = null) {StringBuilder sb = new Stringbu Ilder (); sb.append ("real-time location information: \ n"), sb.append ("longitude:"); sb.append (newlocation.getlongitude ()); sb.append ("\ n latitude:"); Sb.append (newlocation.getlatitude ()); sb.append ("\ n height:"); sb.append (newlocation.getaltitude ()); sb.append ("\ n speed:" ); sb.append (newlocation.getspeed ()); sb.append ("\ n direction:"); sb.append (newlocation.getbearing ()); show.settext ( Sb.tostring ());} else {//if the incoming location object is empty then empty Edittextshow.settext ("");}}</pre><p><p><br><br></p></p><p><p></p></p><p><p>4.<br>Imminent warning:<br>by Locationmanager.addproximityalert (double latitude,double longitude, float radius, long expiration, pendingintent Intent) Add a proximity warning</p></p><p><p>Parameters:</p></p><p><p>Latitude: Specifies the longitude of the fixed point<br>longitude: Specifies the latitude of a fixed point<br>Radius: radius length<br>Expiration: This parameter specifies the number of milliseconds after which the proximity warning Expires.<br>Intent: This parameter specifies the component that the intent corresponds to when it is near the fixed point.</p></p><p><p><br></p></p><p><p>Layout file:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code"><linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools " android:layout_width=" fill_parent " android:layout_height=" fill_parent " android:orientation= "vertical" android:paddingbottom= "@dimen/activity_vertical_margin" android: paddingleft= "@dimen/activity_horizontal_margin" android:paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools:context= " Com.example.proximitytest.ProximityTest "> <textview android:layout_width=" fill_parent " android:layout_height= "wrap_content" android:text= "@string/hello"/></linearlayout></pre></pre><p><p><br></p></p><p><p>Activity:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code">public class Proximitytest extends Activity {@Overrideprotected void OnCreate (Bundle Savedinstancestate) { Super.oncreate (savedinstancestate); setcontentview (r.layout.activity_proximity_test);//location Service constant String locService = Context.location_service;//location Service Manager Instance Locationmanager locationmanager;// Obtain Locationmanager Instance Locationmanager = (locationmanager) getsystemservice (locService) by Getsystemservice method;// Define the approximate longitude and latitude of zibo, shandong, double longitude = 117.3;double latitude = 36.5;//defined radius (5 km) Float radius = 5000;//definition intentintent Intent = n EW Intent (this, proximityalertreciever.class);//package Intent as pendingintentpendingintent pi = Pendingintent.getbroadcast (this,-1, intent, 0);//add proximity warning Locationmanager.addproximityalert (latitude, longitude, radius,-1, pi);}}</pre></pre><p><p><br></p></p><p><p>Proximityalertreciever:</p></p><p><p></p></p><pre class="html" name="code"><pre class="html" name="code">public class Proximityalertreciever extends broadcastreceiver {@Overridepublic void onreceive (context context, Intent Intent) {//gets Whether to enter a specified range of Boolean isenter = Intent.getbooleanextra (locationmanager.key_proximity_entering, false); Isenter) {//display Prompt message Toast.maketext (context, "you have entered Tianhe district, guangzhou", toast.length_long). show ();} Else {//display the prompt message Toast.maketext ( context, "you have left Guangzhou Tianhe district", toast.length_long). Show ();}}}</pre></pre><p><p><br></p></p><p><p>Android------beginner GPS Positioning</p></p></span>