百度地圖查詢視野范圍內(nèi)的建筑物

集微筆記 2013-10-21

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根據(jù)用戶移動(dòng)地圖的位置，顯示在視野范圍內(nèi)的建筑物，簡(jiǎn)單的思路是，添加地圖監(jiān)聽(tīng)，當(dāng)?shù)貓D移動(dòng)結(jié)束之后，計(jì)算出當(dāng)前屏幕四個(gè)角的GeoPoint，根據(jù)這4個(gè)點(diǎn)，通過(guò)mysql的spatial中的函數(shù)，完成在此范圍內(nèi)的建筑物的查詢。

1. mysql spatial介紹

從MySQL4.0開(kāi)始加入了Spatial擴(kuò)展功能，實(shí)現(xiàn)了OpenGIS規(guī)定的幾何數(shù)據(jù)類型，在SQL中的簡(jiǎn)單空間運(yùn)算。但是MySQL對(duì)空間查詢的支持不夠完善，要進(jìn)行復(fù)雜的空間運(yùn)算，建議使用postgreSQL數(shù)據(jù)庫(kù)的postGIS。

下圖是MySQL Spatial接口及類的結(jié)構(gòu)(有背景顏色的框代表接口）：

有關(guān)mysql的詳細(xì)介紹，可以參考一下鏈接中的文章。

l 官方參考文檔（中文）：

http://dev./doc/refman/5.1/zh/spatial-extensions-in-mysql.html#mysql-spatial-datatypes

l 官方參考文檔（英文）：

http://dev./doc/refman/5.0/en/spatial-extensions.html

l 關(guān)于hibernate支持mysql-spatial：

http://blog.csdn.net/b10090120/article/details/8698787

http://www./tutorial.html

拓展mysqlspatial函數(shù)：

1) 空間中的點(diǎn)是否相等

`01`	`DELIMITER $$`

02

`03`	`CREATE` `DEFINER =` `'smart'@'localhost'`

`04`	`FUNCTION` `ArePointsEqual(p1 POINT,`

05 p2POINT

06 )

`07`	`RETURNS` `TINYINT(1)`

`08`	`DETERMINISTIC`

`09`	`NO` `SQL`

10 BEGIN

`11`	`RETURN` `IsZero(x(p1) -x(p2))` `AND` `IsZero(y(p1) - y(p2));`

12 END

13 $$

14

`15`	`DELIMITER ;`

2) 查找區(qū)域的中心點(diǎn)

`01`	`USE smartu;`

02

`03`	`DELIMITER $$`

04

`05`	`CREATE` `DEFINER =` `'smart'@'localhost'`

`06`	`FUNCTION` `GetCenterPoint(g GEOMETRY)`

`07`	`RETURNS` `POINT`

`08`	`DETERMINISTIC`

`09`	`NO` `SQL`

10 BEGIN

`11`	`DECLARE` `envelope POLYGON;`

`12`	`DECLARE` `sw, ne POINT; #South-West` `and` `North-East points`

`13`	`DECLARE` `lat, lng` `DOUBLE;`

14

`15`	`SET` `envelope =exteriorring(Envelope(g));`

`16`	`SET` `sw =pointn(envelope, 1);`

`17`	`SET` `ne =pointn(envelope, 3);`

`18`	`SET` `lat = x(sw) + (x(ne)- x(sw)) / 2;`

`19`	`SET` `lng = y(sw) + (y(ne)- y(sw)) / 2;`

`20`	`RETURN` `POINT(lat, lng);`

21 END

22 $$

23

`24`	`DELIMITER ;`

3) LineN

`01`	`USE smartu;`

02

`03`	`DELIMITER $$`

04

`05`	`CREATE` `DEFINER =` `'smart'@'localhost'`

`06`	`FUNCTION` `LineN(ls LINESTRING,`

07 n INT

08 )

`09`	`RETURNS` `LINESTRING`

`10`	`DETERMINISTIC`

`11`	`NO` `SQL`

12 BEGIN

`13`	`IF n >= numpoints(ls)THEN`

`14`	`RETURN` `NULL;`

`15`	`END` `IF;`

`16`	`RETURNLineString(pointn(ls, n), pointn(ls, n + 1));`

17 END

18 $$

19

`20`	`DELIMITER ;`

4) 計(jì)算兩點(diǎn)間的空間距離

`01`	`USE smartu;`

02

`03`	`DELIMITER $$`

04

`05`	`CREATE` `DEFINER =` `'smart'@'localhost'`

`06`	`FUNCTION` `DISTANCE(lat1` `DOUBLE,`

`07`	`lon1DOUBLE,`

`08`	`lat2DOUBLE,`

`09`	`lon2DOUBLE`

10 )

`11`	`RETURNS` `DOUBLE`

`12`	`DETERMINISTIC`

`13`	`NO` `SQL`

`14`	`COMMENT` `'counts distance (km) between 2 points on Earth surface'`

15 BEGIN

`16`	`DECLARE` `dtor DOUBLEDEFAULT 57.295800;`

17

`18`	`RETURN` `(6371 acos(sin(lat1 / dtor) sin(lat2 / dtor) +`

`19`	`cos(lat1 / dtor) cos(lat2 / dtor) `

`20`	`cos(lon2 / dtor - lon1 /dtor)));`

21 END

22 $$

23

`24`	`DELIMITER ;`

5) 是否為0

`01`	`USE smartu;`

02

`03`	`DELIMITER $$`

04

`05`	`CREATE` `DEFINER =` `'smart'@'localhost'`

`06`	`FUNCTION` `IsZero(n` `DOUBLE)`

`07`	`RETURNS` `TINYINT(1)`

`08`	`DETERMINISTIC`

`09`	`NO` `SQL`

10 BEGIN

`11`	`DECLARE` `epsilon DOUBLEDEFAULT 0.00000000001;`

12

`13`	`RETURN` `(abs(n) <=epsilon);`

14 END

15 $$

16

`17`	`DELIMITER ;`

2. 項(xiàng)目前臺(tái)、后臺(tái)的實(shí)現(xiàn)

1) 項(xiàng)目后臺(tái)實(shí)現(xiàn)

l 數(shù)據(jù)庫(kù)設(shè)計(jì)

`01`	`--創(chuàng)建表`

`02`	`createtable smart_u_convenience_item_spatial(`

`03`	`item_spatial_id` `varchar(36)` `not` `null,`

`04`	`location point` `not` `null,`

`05`	`latitude` `varchar(20),`

`06`	`longitude` `varchar(20),`

`07`	`convenience_item_code` `varchar(500),`

`08`	`convenience_item_name` `varchar(500),`

`09`	`primary` `key` (`item_spatial_id`),

`10`	`spatial` `key` `sp_index`(location)

`11`	`)ENGINE=MyISAM;`

`12`	`--往表中插入數(shù)據(jù)`

`13`	`INSERTINTO smart_u_convenience_item_spatial`

`14`	`SELECTt.convenience_item_id`

`15`	`, PointFromText(concat('POINT(',t.item_latitude,` `' ', t.item_longitude,` `')'))`

`16`	`, t.item_latitude`

`17`	`, t.item_longitude`

`18`	`, t.convenience_item_code`

`19`	`, t.convenience_item_name`

`20`	`from` `smart_u_convenience_item t;`

l 后臺(tái)代碼使用到的查詢點(diǎn)的sql

`01`	`SELECT` `*`

02 FROM

`03`	`(SELECT` `*`

04 FROM

`05`	`smart_u_convenience_item t`

06 WHERE

`07`	`t.convenience_item_idIN`

`08`	`(SELECTs.item_spatial_id`

09 FROM

`10`	`smart_u_convenience_item_spatial s`

11 WHERE

`12`	`intersects(location,`

`13`	`geomfromtext(concat('POLYGON((', 3.9921123E7,` `' ', 1.16365462E8,`

`14`	`',', 3.9921123E7,` `' ', 1.16441881E8,`

`15`	`',', 3.9879484E7,` `' ', 1.16441881E8,`

`16`	`',', 3.9879484E7,` `' ', 1.16365462E8,`

`17`	`',', 3.9921123E7,` `' ', 1.16365462E8,'))'))))) t`

`18`	`ORDER` `BY`

`19`	`item_longitude` `ASC`

2) 前臺(tái)設(shè)計(jì)

001 MKMapViewListener mapViewListener = new MKMapViewListener() {

002

003 @Override

004 public void onMapMoveFinish() {

005 // 此處可以實(shí)現(xiàn)地圖移動(dòng)完成事件的狀態(tài)監(jiān)聽(tīng)

006 Log.e(TAG,"mapMoveFinish");

007 BsnsDisAllActivity.this.getBsnsDisInfo(BsnsDisAllActivity.this.getGeoPointMap());

008 }

009

010 @Override

011 public void onClickMapPoi(MapPoipoi) {

012 Log.e(TAG,poi.geoPt.getLatitudeE6()+","+poi.geoPt.getLongitudeE6());

013 }

014

015 @Override

016 public void onGetCurrentMap(Bitmaparg0) {

017 Log.e(TAG,"onGetCurrentMap");

018

019 }

020

021 @Override

022 public void onMapAnimationFinish(){

023 Log.e(TAG,"onMapAnimationFinish");

024 BsnsDisAllActivity.this.getBsnsDisInfo(BsnsDisAllActivity.this.getGeoPointMap());

025 }

026 };

027 mMapView.regMapViewListener(app.mBMapManager,mapViewListener);

028

029 private Map<String,Double> getGeoPointMap(){

030

031 Projectionprojection = mMapView.getProjection();

032

033 Map<String,Double>polygon = newHashMap<String,Double>();

034 GeoPointtop = projection.fromPixels(0, 0);

035 polygon.put("top_x",(double) top.getLatitudeE6());

036 polygon.put("top_y",(double)top.getLongitudeE6());

037 GeoPointright = projection.fromPixels(mMapView.getWidth(), 0);

038 polygon.put("right_x",(double)right.getLatitudeE6());

039 polygon.put("right_y",(double)right.getLongitudeE6());

040 GeoPointdown = projection.fromPixels(mMapView.getWidth(), mMapView.getHeight());

041 polygon.put("down_x",(double)down.getLatitudeE6());

042 polygon.put("down_y",(double)down.getLongitudeE6());

043 GeoPointleft = projection.fromPixels(0, mMapView.getHeight());

044 polygon.put("left_x",(double)left.getLatitudeE6());

045 polygon.put("left_y",(double)left.getLongitudeE6());

046

047 return polygon;

048 }

049

050

051 private voidgetBsnsDisInfo(Map<String,Double>polygon){

052 final Map<String,Double> tPolygon =polygon;

053 new Thread(){

054 public void run() {

055 try{

056 List<OrderByEntity>orderByEntity = new ArrayList();

057 OrderByEntityorder = newOrderByEntity();

058 order.setOrderCol("item_longitude");

059 order.setOrderType("asc");

060 orderByEntity.add(order);

061 // OrderByEntityorder2 = new OrderByEntity();

062 // order.setOrderCol("item_latitude");

063 // order.setOrderType("asc");

064 // orderByEntity.add(order2);

065

066 ConvenienceItemAckEntityack = SUService.getInstance().getMapBsns(app.nowUser, tPolygon, orderByEntity, null, null);

067 Log.i(TAG,ack.getAckCode().toString());

068 Log.i(TAG,ack.getAckMsg().toString());

069 Message msg = new Message();

070 if(ack.getAckCode().toString().indexOf("INFO") != -1){

071 msg.what = RESULT_BSNS_CAT;

072 }else{

073 msg.what = RESULT_ERROR;

074 }

075 msg.obj = ack;

076 myHandler.sendMessage(msg);

077 }catch(Exception e){

078

079 }

080

081 };

082 }.start();

083 }

084

085 Handler myHandler = new Handler(){

086 public void handleMessage(Messagemsg) {

087 switch (msg.what) {

088 case RESULT_BSNS_CAT:

089 ConvenienceItemAckEntityack = (ConvenienceItemAckEntity)msg.obj;

090 pinItemMark(ack.getResults());

091 break;

092

093 default:

094 break;

095 }

096 };

097 };

098

099 private voidpinItemMark(List<ConvenienceItemEntity> itemList){

100 convenieceItemList= newArrayList<ConvenienceItemEntity>();

101 mGeoList.clear();

102 latLoc.clear();

103 for(inti=0;i<itemList.size();i++){

104 ConvenienceItemEntityitemEntity = itemList.get(i);

105 int lat = Integer.parseInt(itemEntity.getItemLatitude());

106 int loc = Integer.parseInt(itemEntity.getItemLongtude());

107 OverlayItemitem = newOverlayItem(newGeoPoint(lat, loc),itemEntity.getConvenienceItemName() ,itemEntity.getConvenienceItemId());

108

109 ViewdrawableView = LayoutInflater.from(BsnsDisAllActivity.this).inflate(

110 R.layout.map_drawable_pin, null);// 獲取要轉(zhuǎn)換的View資源

111 TextViewTestText = (TextView)drawableView.findViewById(R.id.map_drawable_text);

112 TestText.setText(item.getTitle());//將每個(gè)點(diǎn)的Title在彈窗中以文本形式顯示出來(lái)

113

114 BitmapdrawableBitmap = convertViewToBitmap(drawableView);

115

116 Drawabledraw = newBitmapDrawable(drawableBitmap);

117

118 item.setMarker(draw);

119

120 convenieceItemList.add(itemEntity);

121 mGeoList.add(item);

122 PointlocPoint = newPoint();

123 locPoint.x = i+1;

124 locPoint.y = lat;

125 latLoc.add(locPoint);

126 }

127

128 addMarker(mGeoList);

129 for (int i = 0; i < latLoc.size(); i++){

130 for (int j = 1; j < latLoc.size() - i; j++) {

131 Point p1 = latLoc.get((j-1));

132 Point p2 = latLoc.get(j);

133

134 if(p1.y>p2.y){

135 Point temp = p1;

136 latLoc.set(j-1, p2);

137 latLoc.set(j, p1);

138 }

139 if(latLoc.get(j-1).x==0){

140 selectedItemLat = j-1;

141 }

142 }

143 }

144 }

來(lái)自：http://blog.csdn.net/fengshuiyue/article/details/9155463

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