Android-SDK-dev.zip_android

package android_Examples.ch14.ch14_5; import android.app.Activity; import android.content.Intent; import android.location.Criteria; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.net.Uri; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.TextView; import android.widget.Toast; public class Ch14_5Activity extends Activity { private final int MAX_RECORDS = 10; private LocationManager manager; private Location currentLocation; private String best; private int index = 0, count = 0; private double[] GPLat = new double[MAX_RECORDS]; private double[] GPLng = new double[MAX_RECORDS]; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 取得系统服务的LocationManager对象 manager = (LocationManager)getSystemService(LOCATION_SERVICE); } @Override protected void onResume() { super.onResume(); // 取得最佳的定位提供者 Criteria criteria = new Criteria(); best = manager.getBestProvider(criteria, true); // 更新位置频率的条件 int minTime = 5000; // 毫秒 float minDistance = 15; // 公尺 if (best != null) { // 取得快取的最后位置,如果有的话 currentLocation = manager.getLastKnownLocation(best); manager.requestLocationUpdates(best, minTime, minDistance, listener); } else { // 取得快取的最后位置,如果有的话 currentLocation = manager.getLastKnownLocation(LocationManager.GPS_PROVIDER); manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, minTime, minDistance, listener); } updatePosition(); // 更新位置 } @Override protected void onPause() { super.onPause(); manager.removeUpdates(listener); } // 更新现在的位置 private void updatePosition() { TextView output, list; String str = "最近个人行踪的坐标清单:\n"; output = (TextView) findViewById(R.id.output); list = (TextView) findViewById(R.id.list); if(currentLocation == null) { output.setText("取得定位信息中..."); } else { // 先下目前经纬度坐标信息 output.setText(getLocationInfo(currentLocation)); // 显示个人行踪的坐标清单 for (int i = 0; i < MAX_RECORDS; i++) { if (GPLat[i] != 0.0) str += GPLat[i] + "/" + GPLng[i] +"\n"; } list.setText(str); } } // 创建定位服务的监听者对象 private LocationListener listener = new LocationListener() { @Override public void onLocationChanged(Location location) { currentLocation = location; updatePosition(); } @Override public void onProviderDisabled(String provider) { } @Override public void onProviderEnabled(String provider) { } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } }; // 取得定位信息 public String getLocationInfo(Location location) { boolean isSave = true; double lat, lng; lat = location.getLatitude(); lng = location.getLongitude(); StringBuffer str = new StringBuffer(); str.append("定位提供者(Provider): "+location.getProvider()); str.append("\n纬度(Latitude): " + Double.toString(lat)); str.append("\n经度(Longitude): " + Double.toString(lng)); if (count >= 1) { // 检查是否需要储存坐标 // 创建目地GPS坐标的Location对象 Location dest = new Location(location); // 前一个坐标的数组索引 int preIndex = index - 1; // 检查前一坐标是否是数组最后一个元素 if (preIndex < 0 ) preIndex = GPLat.length - 1; // 设置目的Location对象的坐标 dest.setLatitude(GPLat[preIndex]); dest.setLongitude(GPLng[preIndex]); Log.d("Ch14_5", count + " index/preIndex: " + index +"/" +preIndex); Log.d("Ch14_5", "dlat: " + GPLat[preIndex]); Log.d("Ch14_5", "dlng: " + GPLng[preIndex]); // 计算与目地坐标的距离 float distance = location.distanceTo(dest); Toast.makeText(this, "距离: " + distance + "公尺", Toast.LENGTH_SHORT).show(); Log.d("Ch14_5", "distance: " + distance); // 检查距离是否小于 20公尺, 小于不用存 if (distance < 20.0) isSave = false; } if (isSave) { // 记录坐标 GPLat[index] = lat; GPLng[index] = lng; count++; if (count >= MAX_RECORDS) count = MAX_RECORDS; index++; // 数组索引加一 // 如果索引大于最大索引, 重设为0 if (index >= MAX_RECORDS) index = 0; } return str.toString(); } // 启动Google地图 public void button1_Click(View view) { // 取得经纬度坐标 float latitude = (float) currentLocation.getLatitude(); float longitude = (float) currentLocation.getLongitude(); // 创建 URI字符串 String uri = String.format("geo:%f,%f?z=18", latitude, longitude); // 创建Intent对象 Intent geoMap = new Intent(Intent.ACTION_VIEW,Uri.parse(uri)); startActivity(geoMap); // 启动活动 } // 在MapView组件显示个人行踪 public void button2_Click(View view) { // 创建 Intent对象 Intent mapView = new Intent(this, MyMapActivity.class); mapView.putExtra("GPSLATITUDE", GPLat); mapView.putExtra("GPSLONGITUDE", GPLng); mapView.putExtra("MAX_INDEX", count); startActivity(mapView); // 启动活动 } }