JAVA高级面试进阶训练营视频教程

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近来开发的项目涉及地图位置分享模块，android组的同事先开工，用的是百度地图sdk，本人后面开工，用的是iOS SDK的mapkit做，之后问题来了，同一个经纬度坐标在iOS端和Android端出现了比较大偏差。查了下资料苹果地图在大陆的数据源是高德的，查了下高德采用GCJ-02, 百度map sdk 采用的是BD-09，只好写了个类在发送和接收时做好转换，略微蛋疼。Github上有人写了一个现成的转换类，可以参考参考  传送门 ，其主要代码见下： 

头文件：

#import <Foundation/Foundation.h> #import <CoreLocation/CoreLocation.h> @interface JZLocationConverter : NSObject /** * @brief 世界标准地理坐标(WGS-84) 转换成 中国国测局地理坐标（GCJ-02）<火星坐标> * * ####只在中国大陆的范围的坐标有效，以外直接返回世界标准坐标 * * @param location 世界标准地理坐标(WGS-84) * * @return 中国国测局地理坐标（GCJ-02）<火星坐标> */ + (CLLocationCoordinate2D)wgs84ToGcj02:(CLLocationCoordinate2D)location; /** * @brief 中国国测局地理坐标（GCJ-02） 转换成 世界标准地理坐标（WGS-84） * * ####此接口有1－2米左右的误差，需要精确定位情景慎用 * * @param location 中国国测局地理坐标（GCJ-02） * * @return 世界标准地理坐标（WGS-84） */ + (CLLocationCoordinate2D)gcj02ToWgs84:(CLLocationCoordinate2D)location; /** * @brief 世界标准地理坐标(WGS-84) 转换成 百度地理坐标（BD-09) * * @param location 世界标准地理坐标(WGS-84) * * @return 百度地理坐标（BD-09) */ + (CLLocationCoordinate2D)wgs84ToBd09:(CLLocationCoordinate2D)location; /** * @brief 中国国测局地理坐标（GCJ-02）<火星坐标> 转换成 百度地理坐标（BD-09) * * @param location 中国国测局地理坐标（GCJ-02）<火星坐标> * * @return 百度地理坐标（BD-09) */ + (CLLocationCoordinate2D)gcj02ToBd09:(CLLocationCoordinate2D)location; /** * @brief 百度地理坐标（BD-09) 转换成 中国国测局地理坐标（GCJ-02）<火星坐标> * * @param location 百度地理坐标（BD-09) * * @return 中国国测局地理坐标（GCJ-02）<火星坐标> */ + (CLLocationCoordinate2D)bd09ToGcj02:(CLLocationCoordinate2D)location; /** * @brief 百度地理坐标（BD-09) 转换成 世界标准地理坐标（WGS-84） * * ####此接口有1－2米左右的误差，需要精确定位情景慎用 * * @param location 百度地理坐标（BD-09) * * @return 世界标准地理坐标（WGS-84） */ + (CLLocationCoordinate2D)bd09ToWgs84:(CLLocationCoordinate2D)location; @end

实现文件

#import "JZLocationConverter.h" #import <CoreLocation/CoreLocation.h> #define LAT_OFFSET_0(x,y) -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(fabs(x)) #define LAT_OFFSET_1 (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0 #define LAT_OFFSET_2 (20.0 * sin(y * M_PI) + 40.0 * sin(y / 3.0 * M_PI)) * 2.0 / 3.0 #define LAT_OFFSET_3 (160.0 * sin(y / 12.0 * M_PI) + 320 * sin(y * M_PI / 30.0)) * 2.0 / 3.0 #define LON_OFFSET_0(x,y) 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(fabs(x)) #define LON_OFFSET_1 (20.0 * sin(6.0 * x * M_PI) + 20.0 * sin(2.0 * x * M_PI)) * 2.0 / 3.0 #define LON_OFFSET_2 (20.0 * sin(x * M_PI) + 40.0 * sin(x / 3.0 * M_PI)) * 2.0 / 3.0 #define LON_OFFSET_3 (150.0 * sin(x / 12.0 * M_PI) + 300.0 * sin(x / 30.0 * M_PI)) * 2.0 / 3.0 #define RANGE_LON_MAX 137.8347 #define RANGE_LON_MIN 72.004 #define RANGE_LAT_MAX 55.8271 #define RANGE_LAT_MIN 0.8293 // jzA = 6378245.0, 1/f = 298.3 // b = a * (1 - f) // ee = (a^2 - b^2) / a^2; #define jzA 6378245.0 #define jzEE 0.00669342162296594323 @implementation JZLocationConverter + (double)transformLat:(double)x bdLon:(double)y { double ret = LAT_OFFSET_0(x, y); ret += LAT_OFFSET_1; ret += LAT_OFFSET_2; ret += LAT_OFFSET_3; return ret; } + (double)transformLon:(double)x bdLon:(double)y { double ret = LON_OFFSET_0(x, y); ret += LON_OFFSET_1; ret += LON_OFFSET_2; ret += LON_OFFSET_3; return ret; } + (BOOL)outOfChina:(double)lat bdLon:(double)lon { if (lon < RANGE_LON_MIN || lon > RANGE_LON_MAX) return true; if (lat < RANGE_LAT_MIN || lat > RANGE_LAT_MAX) return true; return false; } + (CLLocationCoordinate2D)gcj02Encrypt:(double)ggLat bdLon:(double)ggLon { CLLocationCoordinate2D resPoint; double mgLat; double mgLon; if ([self outOfChina:ggLat bdLon:ggLon]) { resPoint.latitude = ggLat; resPoint.longitude = ggLon; return resPoint; } double dLat = [self transformLat:(ggLon - 105.0)bdLon:(ggLat - 35.0)]; double dLon = [self transformLon:(ggLon - 105.0) bdLon:(ggLat - 35.0)]; double radLat = ggLat / 180.0 * M_PI; double magic = sin(radLat); magic = 1 - jzEE * magic * magic; double sqrtMagic = sqrt(magic); dLat = (dLat * 180.0) / ((jzA * (1 - jzEE)) / (magic * sqrtMagic) * M_PI); dLon = (dLon * 180.0) / (jzA / sqrtMagic * cos(radLat) * M_PI); mgLat = ggLat + dLat; mgLon = ggLon + dLon; resPoint.latitude = mgLat; resPoint.longitude = mgLon; return resPoint; } + (CLLocationCoordinate2D)gcj02Decrypt:(double)gjLat gjLon:(double)gjLon { CLLocationCoordinate2D gPt = [self gcj02Encrypt:gjLat bdLon:gjLon]; double dLon = gPt.longitude - gjLon; double dLat = gPt.latitude - gjLat; CLLocationCoordinate2D pt; pt.latitude = gjLat - dLat; pt.longitude = gjLon - dLon; return pt; } + (CLLocationCoordinate2D)bd09Decrypt:(double)bdLat bdLon:(double)bdLon { CLLocationCoordinate2D gcjPt; double x = bdLon - 0.0065, y = bdLat - 0.006; double z = sqrt(x * x + y * y) - 0.00002 * sin(y * M_PI); double theta = atan2(y, x) - 0.000003 * cos(x * M_PI); gcjPt.longitude = z * cos(theta); gcjPt.latitude = z * sin(theta); return gcjPt; } +(CLLocationCoordinate2D)bd09Encrypt:(double)ggLat bdLon:(double)ggLon { CLLocationCoordinate2D bdPt; double x = ggLon, y = ggLat; double z = sqrt(x * x + y * y) + 0.00002 * sin(y * M_PI); double theta = atan2(y, x) + 0.000003 * cos(x * M_PI); bdPt.longitude = z * cos(theta) + 0.0065; bdPt.latitude = z * sin(theta) + 0.006; return bdPt; } + (CLLocationCoordinate2D)wgs84ToGcj02:(CLLocationCoordinate2D)location { return [self gcj02Encrypt:location.latitude bdLon:location.longitude]; } + (CLLocationCoordinate2D)gcj02ToWgs84:(CLLocationCoordinate2D)location { return [self gcj02Decrypt:location.latitude gjLon:location.longitude]; } + (CLLocationCoordinate2D)wgs84ToBd09:(CLLocationCoordinate2D)location { CLLocationCoordinate2D gcj02Pt = [self gcj02Encrypt:location.latitude bdLon:location.longitude]; return [self bd09Encrypt:gcj02Pt.latitude bdLon:gcj02Pt.longitude] ; } + (CLLocationCoordinate2D)gcj02ToBd09:(CLLocationCoordinate2D)location { return [self bd09Encrypt:location.latitude bdLon:location.longitude]; } + (CLLocationCoordinate2D)bd09ToGcj02:(CLLocationCoordinate2D)location { return [self bd09Decrypt:location.latitude bdLon:location.longitude]; } + (CLLocationCoordinate2D)bd09ToWgs84:(CLLocationCoordinate2D)location { CLLocationCoordinate2D gcj02 = [self bd09ToGcj02:location]; return [self gcj02Decrypt:gcj02.latitude gjLon:gcj02.longitude]; } @end

测试用例：

CLLocationCoordinate2D gcj02 = CLLocationCoordinate2DMake(114.21892734521,29.575429778924); CLLocationCoordinate2D bd09 = [JZLocationConverter gcj02ToBd09:gcj02]; NSLog(@"%f,%f", bd09.latitude, bd09.longitude); // http://developer.baidu.com/map/index.php?title=webapi/guide/changeposition // JZLocationConverter 测试数据: 114.21892734521,29.575429778924 ; 转化结果: 114.224960,29.581853 // 百度api 测试数据: 114.21892734521,29.575429778924 ; 百度api转换结果: 114.22539195429,29.581585367458

总体来说，存在一点偏差，但跟处理前的效果比一下，相对可以接受了些。

参考：

http://blog.csdn.net/jiajiayouba/article/details/25140967

http://developer.baidu.com/map/index.php?title=webapi/guide/changeposition 

http://blog.csdn.net/winnyrain/article/details/22233559 

http://www.kuaifenxiang.net/article/17 

http://blog.csdn.net/coolypf/article/details/8569813 

http://www.cppblog.com/socketref/archive/2011/06/29/149713.html