一： MKMapView的缩放等级

1.创建缩放按钮

@property (nonatomic,strong)UIButton *zoomInBtn; //放大
@property (nonatomic,strong)UIButton *zoomOutBtn;//缩小

方法：
//放大方法

-(void)mapZoomIn {
MKCoordinateRegion region = self.map.region;
region.span.latitudeDelta = region.span.latitudeDelta * 0.5;
region.span.longitudeDelta = region.span.longitudeDelta * 0.5;
[self.map setRegion:region animated:YES];
}

//缩小方法

-(void)mapZoomOut {
MKCoordinateRegion region = self.map.region;
region.span.latitudeDelta = region.span.latitudeDelta * 2;
region.span.longitudeDelta = region.span.longitudeDelta * 2;
[self.map setRegion:region animated:YES];
}

二： 经纬度转换

#import "WGS84TOGCJ02.h"

const double a = 6378245.0;
const double ee = 0.00669342162296594323;
const double pi = 3.14159265358979324;

 @implementation WGS84TOGCJ02

 +(CLLocationCoordinate2D)transformFromWGSToGCJ:(CLLocationCoordinate2D)wgsLoc
{
CLLocationCoordinate2D adjustLoc;

double adjustLat = [self transformLatWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
double adjustLon = [self transformLonWithX:wgsLoc.longitude - 105.0 withY:wgsLoc.latitude - 35.0];
double radLat = wgsLoc.latitude / 180.0 * pi;
double magic = sin(radLat);
magic = 1 - ee * magic * magic;
double sqrtMagic = sqrt(magic);
adjustLat = (adjustLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
adjustLon = (adjustLon * 180.0) / (a / sqrtMagic * cos(radLat) * pi);
adjustLoc.latitude = wgsLoc.latitude + adjustLat;
adjustLoc.longitude = wgsLoc.longitude + adjustLon;

return adjustLoc;
}

 +(double)transformLatWithX:(double)x withY:(double)y
{
double lat = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * sqrt(fabs(x));
lat += (20.0 * sin(6.0 * x * pi) + 20.0 *sin(2.0 * x * pi)) * 2.0 / 3.0;
lat += (20.0 * sin(y * pi) + 40.0 * sin(y / 3.0 * pi)) * 2.0 / 3.0;
lat += (160.0 * sin(y / 12.0 * pi) + 320 * sin(y * pi / 30.0)) * 2.0 / 3.0;
return lat;
}

+(double)transformLonWithX:(double)x withY:(double)y
{
double lon = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * sqrt(fabs(x));
lon += (20.0 * sin(6.0 * x * pi) + 20.0 * sin(2.0 * x * pi)) * 2.0 / 3.0;
lon += (20.0 * sin(x * pi) + 40.0 * sin(x / 3.0 * pi)) * 2.0 / 3.0;
lon += (150.0 * sin(x / 12.0 * pi) + 300.0 * sin(x / 30.0 * pi)) * 2.0 / 3.0;
return lon;
}

@end