依据Latitude/Longitude 计算方位...- （4）布局

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▪依据Latitude/Longitude 计算方位，距离等根据Latitude/Longitude 计算方位，距离等里面有详细的说明http://www.movable-type.co.uk/scripts/latlong.html比如计算距离方法一，double dist = 0.0; double deltaLat = Math.toRadians(latVal2 - latVal1); .........

▪ （4）布局（四）布局 padding:描述控件里面的内容与控件的关机，内边距；有四个方向属性；paddingleft...... layout_margin:描述控件之间的位置关系，外边距；有四个方向属性；layout_margingleft..... gravity:设.........

▪ 位置服务的打包位置服务的封装 /** * Retrieve accurate location from GPS or network services. * * * Class usage example: * * public void onCreate(Bundle savedInstanceState) { * ... * my_location = new MyLocation(); * my_location.init.........

[1]依据Latitude/Longitude 计算方位，距离等

来源: 互联网发布时间: 2014-02-18

根据Latitude/Longitude 计算方位，距离等
里面有详细的说明http://www.movable-type.co.uk/scripts/latlong.html
比如计算距离
方法一，

double dist = 0.0; 
             double deltaLat = Math.toRadians(latVal2 - latVal1); 
             double deltaLon = Math.toRadians(lonVal2 - lonVal1); 
             latVal1 = Math.toRadians(latVal1); 
             latVal2 = Math.toRadians(latVal2); 
             lonVal1 = Math.toRadians(lonVal1); 
             lonVal2 = Math.toRadians(lonVal2); 
                double earthRadius = 6371; 
                double a = Math.sin(deltaLat/2) * Math.sin(deltaLat/2) + 
Math.cos(latVal1) * Math.cos(latVal2) * Math.sin(deltaLon/2) * Math.sin 
(deltaLon/2); 
                double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
                dist = earthRadius * c;

方法二，

public static double calculateHaversineMI(double lat1, double long1, double lat2,double long2) {
	    double dlong = (long2 - long1) * (Math.PI / 180.0f);
	    double dlat = (lat2 - lat1) * (Math.PI / 180.0f);
	    double a = Math.pow(Math.sin(dlat / 2.0), 2)
	        + Math.cos(lat1 * (Math.PI / 180.0f))
	        * Math.cos(lat2 * (Math.PI / 180.0f))
	        * Math.pow(Math.sin(dlong / 2.0), 2);
	    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
	    double d = 6367* c;

	    return d;
	}

还有计算方位

double dLong = picLongitude - mLongitude; 
double y =  (Math.sin(dLong) * Math.cos(picLatitude)); 
double x =  (Math.cos(mLatitude) * Math.sin(picLatitude) - 
Math.sin(mLatitude)*Math.cos(picLatitude)*Math.cos(dLong)); 
double angleDegreesWrongRange = Math.abs(Math.toDegrees(Math.atan2(y, 
x))); 
float angleDegrees = (float) ((angleDegreesWrongRange+360) % 360);

	public static String getDirection(float baseAzimuth){
		String bearingText = "";
	    if ( (360 >= baseAzimuth && baseAzimuth >= 337.5) || (0 <= baseAzimuth && baseAzimuth <= 22.5) ) bearingText = "N";
	    else if (baseAzimuth > 22.5 && baseAzimuth < 67.5) bearingText = "NE";
	    else if (baseAzimuth >= 67.5 && baseAzimuth <= 112.5) bearingText = "E";
	    else if (baseAzimuth > 112.5 && baseAzimuth < 157.5) bearingText = "SE";
	    else if (baseAzimuth >= 157.5 && baseAzimuth <= 202.5) bearingText = "S";
	    else if (baseAzimuth > 202.5 && baseAzimuth < 247.5) bearingText = "SW";
	    else if (baseAzimuth >= 247.5 && baseAzimuth <= 292.5) bearingText = "W";
	    else if (baseAzimuth > 292.5 && baseAzimuth < 337.5) bearingText = "NW";
	    
	    return bearingText;
	}

都可以在里面找到答案

[2] （4）布局

来源: 互联网发布时间: 2014-02-18

（四）布局

padding:描述控件里面的内容与控件的关机，内边距；有四个方向属性；paddingleft......

layout_margin:描述控件之间的位置关系，外边距；有四个方向属性；layout_margingleft.....

gravity:设置该控件的对齐方式；

layout_gravity:设置它在父控件中的对齐方式；

尺寸：

FrameLayout(框架布局)

LinearLayout (线性布局)

linearLayout中有一个重要的属性 android:layout_weight="1"，这个weight在垂直布局时，代表行距；

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　水平的时候代表列宽；weight值越大就越大。

属性值为具体的像素值，如30dip，40px (建议用dip)

android:layout_marginBottom 离某元素底边缘的距离
android:layout_marginLeft 离某元素左边缘的距离

android:layout_marginRight 离某元素右边缘的距离
android:layout_marginTop 离某元素上边缘的距离

AbsoluteLayout(绝对布局)：

犹如div指定了absolute属性

用X,Y坐标来指定元素的位置

android:layout_x="20px"

android:layout_y="12px"

RelativeLayout(相对布局),

android:layout_above=“@+id/给定的ID” 　将该控件的底部至于给定ID的控件之上

android:layout_below 　　　　　　将该控件的顶部至于给定ID的控件之下

android:layout_toLeftOf 　　　　　　将该控件的右边缘和给定ID的控件的左边缘对齐

android:layout_toRightOf 　　　　　　　将该控件的左边缘和给定ID的控件的右边缘对齐

android:layout_alignBaseline 　该控件的baseline和给定ID的控件的baseline对齐

android:layout_alignBottom 　底部边缘与给定ID控件的底部边缘

android:layout_alignLeft 　左边缘与给定ID控件的左边缘对齐

android:layout_alignRight 　右边缘与给定ID控件的右边缘对齐

android:layout_alignTop 　将顶部边缘与给定ID控件的顶部对齐

android:alignParentBottom 如果该值为true，底部和父控件的底部对齐

android:layout_alignParentLeft 如果该值为true，左边与父控件的左边对齐

android:layout_alignParentRight 如果该值为true，右边与父控件的右边对齐

android:layout_alignParentTop 如果该值为true，顶部与父控件的顶部对齐

android:layout_centerHorizontal 如果值为真，该控件将被至于水平方向的中央

android:layout_centerVertical 如果值为真，该控件将被至于垂直方向的中央

android:layout_centerInParent 如果值为真，该控件将被至于父控件水平方向和垂直方向的中央

TableLayout(表格布局) 。

表格布局类似Html里面的Table。每一个TableLayout里面有表格行TableRow，TableRow里面可以具体定义每一个元素，设定他的对齐方式 android:gravity="" 。

TableLayout置底，TableRow在TableLayout的上面
Button、TextView等控件就在TableRow之上
TableLayout之上也可以单独放控件

android:collapseColumns=0,1：以第0行为序，隐藏指定的列：隐藏第0列，第一列；
android:shrinkColumns：将指定的列设为可收缩的列，该列会收缩至适应屏幕;
android:stretchColumns：将指定的列设为可伸展的列，该列会尽量伸展以填满空间
android:layout_column:控件在TableRow中所处的列
android:layout_span:控件所跨越的列数

这五个布局元素可以相互嵌套应用，做出美观的界面。

Layout用到的一些重要的属性

android:textSize        指定控件当中字体的大小
android:background      指定该控件所使用的背景色，RGB命名法
android:width           指定控件的宽度
android:height          指定控件的高度

android:layout_width    指定Container组件的宽度
android:layout_height   指定Container组件的高度
android:layout_weight   View中很重要的属性，按比例划分空间

android:sigleLine 如果设置为真的话，则控件的内容在同一行中进行显示
android:scaleType 是控制图片如何resized/moved来匹对ImageView的siz

android:layout_alignWithParentIfMissing 如果对应的兄弟元素找不到的话就以父元素做参照物

android:layout_marginBottom        离某元素底边缘的距离
android:layout_marginLeft          离某元素左边缘的距离
android:layout_marginRight         离某元素右边缘的距离
android:layout_marginTop           离某元素上边缘的距离

EditText的android:hint 设置EditText为空时输入框内的提示信息。

android:scaleType：是控制图片如何resized/moved来匹对ImageView的size。
ImageView.ScaleType / android:scaleType值的意义区别：
CENTER /center 按图片的原来size居中显示，当图片长/宽超过View的长/宽，则截取图片的居中部分显示
CENTER_CROP / centerCrop 按比例扩大图片的size居中显示，使得图片长(宽)等于或大于View的长(宽)
CENTER_INSIDE / centerInside 将图片的内容完整居中显示，通过按比例缩小或原来的size使得图片长/宽等于或小于View的长/宽
FIT_CENTER / fitCenter 把图片按比例扩大/缩小到View的宽度，居中显示
FIT_END / fitEnd 把图片按比例扩大/缩小到View的宽度，显示在View的下部分位置
FIT_START / fitStart 把图片按比例扩大/缩小到View的宽度，显示在View的上部分位置
FIT_XY / fitXY 把图片不按比例扩大/缩小到View的大小显示
MATRIX / matrix 用矩阵来绘制，动态缩小放大图片来显示。

[3] 位置服务的打包

来源: 互联网发布时间: 2014-02-18

位置服务的封装

/**
 * Retrieve accurate location from GPS or network services. 
 * 
 *
 * Class usage example:
 * 
 * public void onCreate(Bundle savedInstanceState) {
 *      ...
 *      my_location = new MyLocation();
 *      my_location.init(main.this, locationResult);
 * }
 * 
 * 
 * public LocationResult locationResult = new LocationResult(){
 *      @Override
 *      public void gotLocation(final Location location){
 *          // do something
 *          location.getLongitude();
 *          location.getLatitude();
 *      }
 *  };
 */
public class MyLocations{

    /**
     * If GPS is enabled. 
     * Use minimal connected satellites count.
     */
    private static final int min_gps_sat_count = 5;

    /**
     * Iteration step time.
     */
    private static final int iteration_timeout_step = 500;

    LocationResult locationResult;
    private Location bestLocation = null;
    private Handler handler = new Handler();
    private LocationManager myLocationManager; 
    public Context context;

    private boolean gps_enabled = false;

    private int counts    = 0;
    private int sat_count = 0;

    private Runnable showTime = new Runnable() {

         public void run() {
            boolean stop = false;
            counts++;
            System.out.println("counts=" + counts);

            //if timeout (1 min) exceeded, stop tying
            if(counts > 120){
                stop = true;
            }

            //update last best location
            bestLocation = getLocation(context);

            //if location is not ready or don`t exists, try again
            if(bestLocation == null && gps_enabled){
                System.out.println("BestLocation not ready, continue to wait");
                handler.postDelayed(this, iteration_timeout_step);
            }else{
                //if best location is known, calculate if we need to continue to look for better location
                //if gps is enabled and min satellites count has not been connected or min check count is smaller then 4 (2 sec)  
                if(stop == false && !needToStop()){
                    System.out.println("Connected " + sat_count + " sattelites. continue waiting..");
                    handler.postDelayed(this, iteration_timeout_step);
                }else{
                    System.out.println("#########################################");
                    System.out.println("BestLocation finded return result to main. sat_count=" + sat_count);
                    System.out.println("#########################################");

                    // removing all updates and listeners
                    myLocationManager.removeUpdates(gpsLocationListener);
                    myLocationManager.removeUpdates(networkLocationListener);    
                    myLocationManager.removeGpsStatusListener(gpsStatusListener);
                    sat_count = 0;

                    // send best location to locationResult
                    locationResult.gotLocation(bestLocation);
                }
            }
         }
    };

    /**
     * Determine if continue to try to find best location
     */
    private Boolean needToStop(){

        if(!gps_enabled){
                          return true;
                     }
          else if(counts <= 4){
                return false;
            }
            if(sat_count < min_gps_sat_count){
                //if 20-25 sec and 3 satellites found then stop
                if(counts >= 40 && sat_count >= 3){
                    return true;
                }
                return false;
            }
//        }
        return true;
    }

    /**
     * Best location abstract result class
     */
    public static abstract class LocationResult{
         public abstract void gotLocation(Location location);
     }

    /**
     * Initialize starting values and starting best location listeners
     * 
     * @param Context ctx
     * @param LocationResult result
     */
    public void init(Context ctx, LocationResult result){
        context = ctx;
        locationResult = result;

        myLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

        gps_enabled = (Boolean) myLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

        bestLocation = null;
        counts = 0;

        // turning on location updates
        myLocationManager.requestLocationUpdates("network", 0, 0, networkLocationListener);
        myLocationManager.requestLocationUpdates("gps", 0, 0, gpsLocationListener);
        myLocationManager.addGpsStatusListener(gpsStatusListener);

        // starting best location finder loop
        handler.postDelayed(showTime, iteration_timeout_step);
    }

    /**
     * GpsStatus listener. OnChainged counts connected satellites count.
     */
    public final GpsStatus.Listener gpsStatusListener = new GpsStatus.Listener() {
        public void onGpsStatusChanged(int event) {

             if(event == GpsStatus.GPS_EVENT_SATELLITE_STATUS){
                try {
                    // Check number of satellites in list to determine fix state
                     GpsStatus status = myLocationManager.getGpsStatus(null);
                     Iterable<GpsSatellite>satellites = status.getSatellites();

                     sat_count = 0;

                     Iterator<GpsSatellite>satI = satellites.iterator();
                     while(satI.hasNext()) {
                         GpsSatellite satellite = satI.next();
                         System.out.println("Satellite: snr=" + satellite.getSnr() + ", elevation=" + satellite.getElevation());                         
                         sat_count++;
                     }
                } catch (Exception e) {
                    e.printStackTrace();
                    sat_count = min_gps_sat_count + 1;
                }

                 System.out.println("#### sat_count = " + sat_count);
             }
         }
    };

    /**
     * Gps location listener.
     */
    public final LocationListener gpsLocationListener = new LocationListener(){
        public void onLocationChanged(Location location){

        }
         public void onProviderDisabled(String provider){}
         public void onProviderEnabled(String provider){}
         public void onStatusChanged(String provider, int status, Bundle extras){}
    }; 

    /**
     * Network location listener.
     */
    public final LocationListener networkLocationListener = new LocationListener(){
        public void onLocationChanged(Location location){

        }
         public void onProviderDisabled(String provider){}
         public void onProviderEnabled(String provider){}
         public void onStatusChanged(String provider, int status, Bundle extras){}
    }; 


    /**
     * Returns best location using LocationManager.getBestProvider()
     * 
     * @param context
     * @return Location|null
     */
    public static Location getLocation(Context context){
        System.out.println("getLocation()");

        // fetch last known location and update it
        try {
            LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

            Criteria criteria = new Criteria();
            criteria.setAccuracy(Criteria.ACCURACY_FINE);
             criteria.setAltitudeRequired(false);
             criteria.setBearingRequired(false);
             criteria.setCostAllowed(true);
             String strLocationProvider = lm.getBestProvider(criteria, true);

             System.out.println("strLocationProvider=" + strLocationProvider);
             Location location = lm.getLastKnownLocation(strLocationProvider);
             if(location != null){
                return location;
             }
             return null;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}