Android实现GPS定位代码实例

通过gps取得的是一个location类型的经纬度， 可以转换为两个double 纬度和经度.
纬度: 23.223871812820435
纬度: 113.58986039161628
首先创建一个textview和两个button

<textview 
 android:id="@+id/text"
 android:layout_width="fill_parent" 
  android:layout_height="wrap_content"  />
 
 <button
  android:id="@+id/btnstart"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="定位" />
 <button
  android:id="@+id/btnstop"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="停止" />

然后添加主activity的代码
location 是存放经纬度的一个类型
locationmanager是位置管理服务类型

private button btnstart;
private button btnstop;
private textview textview;
private location mlocation;
private locationmanager mlocationmanager;
/** called when the activity is first created. */
@override
public void oncreate(bundle savedinstancestate)
{
 
 super.oncreate(savedinstancestate);
 setcontentview(r.layout.main);
 
 btnstart = (button)findviewbyid(r.id.btnstart);
 btnstop = (button)findviewbyid(r.id.btnstop);
 textview = (textview)findviewbyid(r.id.text);
 btnstart.setonclicklistener(btnclicklistener); //开始定位
 btnstop.setonclicklistener(btnclicklistener); //结束定位按钮
}
gpsisopen是自己写的查看当前gps是否开启
getlocation 是自己写的一个获取定位信息的方法
mlocationmanager.removeupdates()是停止当前的gps位置监听
public button.onclicklistener btnclicklistener = new button.onclicklistener()
{
 public void onclick(view v)
 {
  button btn = (button)v;
  if(btn.getid() == r.id.btnstart)
  {
   if(!gpsisopen())
    return;
   
  mlocation = getlocation();
   
   if(mlocation != null)
    textview.settext("维度:" + mlocation.getlatitude() + "\n经度:" + mlocation.getlongitude());
   else
    textview.settext("获取不到数据");
  }
  else if(btn.getid() == r.id.btnstop)
  {
   mlocationmanager.removeupdates(locationlistener);
  }

 }
};
private boolean gpsisopen()
{
 boolean bret = true;

 locationmanager alm = (locationmanager)this.getsystemservice(context.location_service);
 if(!alm.isproviderenabled(locationmanager.gps_provider))
 {
  toast.maketext(this, "未开启gps", toast.length_short).show();
  bret = false;
 }
 else 
 {
  toast.maketext(this, "gps已开启", toast.length_short).show();
 }

 return bret;
}
判断当前是否开启gps
private boolean gpsisopen()
{
 boolean bret = true;
 
 locationmanager alm = (locationmanager)this.getsystemservice(context.location_service);
 if(!alm.isproviderenabled(locationmanager.gps_provider))
 {
  toast.maketext(this, "未开启gps", toast.length_short).show();
  bret = false;
 }
 else 
 {
  toast.maketext(this, "gps已开启", toast.length_short).show();
 }

 return bret;
}
该方法获取当前的经纬度， 第一次获取总是null
后面从locationlistener获取已改变的位置
mlocationmanager.requestlocationupdates()是开启一个locationlistener等待位置变化
private location getlocation()
{
 //获取位置管理服务
 mlocationmanager = (locationmanager)this.getsystemservice(context.location_service);

 //查找服务信息
 criteria criteria = new criteria();
 criteria.setaccuracy(criteria.accuracy_fine); //定位精度: 最高
 criteria.setaltituderequired(false); //海拔信息：不需要
 criteria.setbearingrequired(false); //方位信息: 不需要
 criteria.setcostallowed(true);  //是否允许付费
 criteria.setpowerrequirement(criteria.power_low); //耗电量: 低功耗
 
 string provider = mlocationmanager.getbestprovider(criteria, true); //获取gps信息

 location location = mlocationmanager.getlastknownlocation(provider);
 
 mlocationmanager.requestlocationupdates(provider, 2000, 5, locationlistener);
 
 return location;
}
改方法是等待gps位置改变后得到新的经纬度
private final locationlistener locationlistener = new locationlistener()
{
 public void onlocationchanged(location location)
 {
  // todo auto-generated method stub
  if(location != null)
   textview.settext("维度:" + location.getlatitude() + "\n经度:" 
      + location.getlongitude());
  else
   textview.settext("获取不到数据" + integer.tostring(ncount));
 }

 public void onproviderdisabled(string provider)
 {
  // todo auto-generated method stub
 }

 public void onproviderenabled(string provider)
 {
  // todo auto-generated method stub
 }

 public void onstatuschanged(string provider, int status, bundle extras)
 {
  // todo auto-generated method stub
  
 }
};