自定义类 WMSTileOverlayUtil，继承自高德地图接口 MATileOverlay，主要重载函数：

- (NSURL *)URLForTilePath:(MATileOverlayPath)path;

- (void)loadTileAtPath:(MATileOverlayPath)path result:(void (^)(NSData *tileData, NSError *error))result;，见代码注释。

#import

#import

@interface WMSTileOverlayUtil : MATileOverlay

- (id)initWithRootURL:(NSString *)rootRUL;

/**

*@brief 以tile path生成URL。用于加载tile,此方法默认填充URLTemplate

*@param path tile path

*@return 以tile path生成tileOverlay

*/

- (NSURL *)URLForTilePath:(MATileOverlayPath)path;

@end

#import "WMSTileOverlayUtil.h"

#import

#import

#import

#import "Api.h"

@implementation WMSTileOverlayUtil

{

NSString * rootURL;

NSInteger titleSize; // = 256

double initialResolution; // = 156543.03392804062;//2*Math.PI*6378137/titleSize;

double originShift; // = 20037508.342789244;//2*Math.PI*6378137/2.0; 周长的一半

double HALF_PI; // = Math.PI / 2.0;

double RAD_PER_DEGREE; // = Math.PI / 180.0;

double METER_PER_DEGREE; // = originShift / 180.0;//一度多少米

double DEGREE_PER_METER; // = 180.0 / originShift;//一米多少度

}

- (id)initWithRootURL:(NSString *)rootRUL {

self = [super init];

if (self) {

rootURL = rootRUL;

titleSize = 256;

initialResolution = 156543.03392804062;

originShift = 20037508.342789244;

HALF_PI = M_PI_2;

RAD_PER_DEGREE = M_PI / 180.0;

METER_PER_DEGREE = originShift / 180.0;

DEGREE_PER_METER = 180.0 / originShift;

}

return self;

}

/**

*@brief 以tile path生成URL。用于加载tile,此方法默认填充URLTemplate

*@param path tile path

*@return 以tile path生成tileOverlay

*/

- (NSURL *)URLForTilePath:(MATileOverlayPath)path {

NSString * strURL = [[NSString alloc] initWithFormat:@"%@%@", rootURL, [self titleBoundsByX:path.x

Y:path.y

Z:path.z]];

NSURL * url = [NSURL URLWithString:strURL];

return url;

}

/**

*@brief 加载被请求的tile,并以tile数据或加载tile失败error访问回调block;默认实现为首先用URLForTilePath去获取URL,然后用异步NSURLConnection加载tile

*@param path tile path

*@param result 用来传入tile数据或加载tile失败的error访问的回调block

*/

- (void)loadTileAtPath:(MATileOverlayPath)path result:(void (^)(NSData *tileData, NSError *error))result {

if (path.z < 8) return;

NSURL * url = [self URLForTilePath:path];

NSString * strURL = url.absoluteString;

SuccessCallback successCallback = ^(id responseObject) {

UIImage * image = [UIImage imageWithData:responseObject];

NSData * data = UIImagePNGRepresentation(image);

result(data, nil);

};

FailureCallBack failureCallBack = ^(NSError *error) {

result(nil, error);

};

[Api GETWMSWith:strURL successCallback:successCallback failureCallBack:failureCallBack];

}

/**

*@brief 取消请求瓦片，当地图显示区域发生变化时，会取消显示区域外的瓦片的下载, 当disableOffScreenTileLoading=YES时会被调用。since 5.3.0

*@param path tile path

*/

- (void)cancelLoadOfTileAtPath:(MATileOverlayPath)path {

[super cancelLoadOfTileAtPath:path];

}

/**

* 根据瓦片的x/y等级返回瓦片范围

*

*@param tx x

*@param ty y

*@param zoom z

*@return url

*/

- (NSString *)titleBoundsByX:(NSInteger)tx Y:(NSInteger)ty Z:(NSInteger)zoom {

double minX = [self pixels2Meters:(tx * titleSize) zoom:zoom];

double maxY = -[self pixels2Meters:(ty * titleSize) zoom:zoom];

double maxX = [self pixels2Meters:((tx + 1) * titleSize) zoom:zoom];

double minY = -[self pixels2Meters:((ty + 1) * titleSize) zoom:zoom];

//转换成经纬度

minX = [self meters2Lon:minX];

minY = [self meters2Lat:minY];

maxX = [self meters2Lon:maxX];

maxY = [self meters2Lat:maxY];

//坐标转换工具类构造方法 Gps( WGS-84) 转 为高德地图需要的坐标

CLLocationCoordinate2D amapcoord = AMapCoordinateConvert(CLLocationCoordinate2DMake(minY, minX), AMapCoordinateTypeGPS);

minY = amapcoord.latitude;

minX = amapcoord.longitude;

CLLocationCoordinate2D maxAmapcoord = AMapCoordinateConvert(CLLocationCoordinate2DMake(maxY, maxX), AMapCoordinateTypeGPS);

maxY = maxAmapcoord.latitude;

maxX = maxAmapcoord.longitude;

NSString * result = [[NSString alloc] initWithFormat:@"%f,%f,%f,%f&width=256&height=256", minX, minY, maxX, maxY];

return result;

}

/**

* 根据像素、等级算出坐标

*

*@param p p

*@param zoom z

*@return double

*/

- (double)pixels2Meters:(NSInteger)p zoom:(NSInteger)zoom {

return p * [self resolution:zoom] - originShift;

}

/**

* 计算分辨率

*

*@param zoom z

*@return double

*/

- (double)resolution:(NSInteger)zoom {

return initialResolution / (pow(2, zoom));

}

/**

* X米转经纬度

*/

- (double)meters2Lon:(double)mx {

double lon = mx * DEGREE_PER_METER;

return lon;

}

/**

* Y米转经纬度

*/

- (double)meters2Lat:(double)my {

double lat = my * DEGREE_PER_METER;

lat = 180.0 / M_PI * (2 * atan(exp(lat * RAD_PER_DEGREE)) - HALF_PI);

return lat;

}

@end

其中，- (void)loadTileAtPath:(MATileOverlayPath)path result:(void (^)(NSData *tileData, NSError *error))result; 函数中，使用自己写的 网络访问层去请求 wms 服务，并通过 result 函数贴到地图上。你也可以 改写成自己的网络访问层。

问题

为啥要重载 - (void)loadTileAtPath:(MATileOverlayPath)path result:(void (^)(NSData *tileData, NSError *error))result; 函数，因为只是从载 - (NSURL *)URLForTilePath:(MATileOverlayPath)path; 生成 NSURL 后，loadTileAtPath 函数会去通过网络请求加载 wms 服务，然而，这一步网络请求会报错：NSURLConnection -errorcode -1004，且一个星期没有解决为啥报错，所以只得重写，如果有熟悉高德地图 api 的小伙伴能够给予解答，不胜感激。

注意

如果使用 AFNetworking 要注意修改支持的类型：

AFHTTPSessionManager * manager = [[AFHTTPSessionManager alloc] init];

AFHTTPResponseSerializer *serializer=[AFHTTPResponseSerializer serializer];

serializer.acceptableContentTypes = [NSSet setWithObject:@"image/png"];

manager.responseSerializer = serializer;