Display annotation in Map kit - iphone

Question

I am working with Mapkit and I have to show annotations in the map but I'm not able to display the annotation. Here's my code:
#interface MyMapView : UIViewController <MKAnnotation,MKMapViewDelegate>{
MKMapView *Obj_Map_View;
MKPlacemark *pmark;
MKReverseGeocoder *geocoder1;
}
#end
#import "MyMapView.h"
#implementation MyMapView
- (id)init {
if (self = [super init]) {
}
return self;
}
- (void)loadView {
[super loadView];
Obj_Map_View = [[MKMapView alloc]initWithFrame:self.view.bounds];
Obj_Map_View.showsUserLocation =YES;
Obj_Map_View.mapType=MKMapTypeStandard;
[self.view addSubview:Obj_Map_View];
Obj_Map_View.delegate = self;
CLLocationCoordinate2D cord = {latitude: 19.120000, longitude: 73.020000};
MKCoordinateSpan span = {latitudeDelta:0.3, longitudeDelta:0.3};
MKCoordinateRegion reg= {cord,span};
[Obj_Map_View setRegion:reg animated:YES];
//[Obj_Map_View release];
}
- (NSString *)subtitle{
return #"Sub Title";
}
- (NSString *)title{
return #"Title";
}
- (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>) annotation
{
MKPinAnnotationView *annov = [[MKPinAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:#"Current location"];
annov.animatesDrop = TRUE;
[annotation title]==#"Current location";
annov.canShowCallout = YES;
[annov setPinColor:MKPinAnnotationColorGreen];
return annov;
}
The above code works fine and displays a map but not with annotation.

Answer 1

Typically, the class that conforms to the MKAnnotation protocol isn't the view controller, it's a data class.
You'll need to create another class, which I'll call "MyLandmarks" for the example.
#interface MyLandmarks : NSObject <MKAnnotation>
// Normally, there'd be some variables that contain the name and location.
// And maybe some means to populate them from a URL or a database.
// This example hard codes everything.
#end
#implementation MyLandmarks
-(NSString*)title {
return #"'ere I am, J.H.";
}
-(NSString*)subtitle {
return #"The ghost in the machine.";
}
-(CLLocationCoordinate2D) coordinate {
CLLocationCoordinate2D coord = {latitude: 19.120000, longitude: 73.020000};
return coord;
}
#end
Then, somewhere appropriate in your MyMapView class add:
MyLandmark *landmark = [[[MyLandmark alloc]init]autorelease];
[Obj_Map_View addAnnotation:landmark];
A couple other bits that other Objective-C developers working with you will appreciate:
To avoid confusion, don't call the class MyMapView if it descends from a UIViewController. Call it MyMapViewController, instead.
Classes start with a capital letter, variables start lowercase. Both are CamelCased. Obj_Map_View should be objMapView.

Answer 2

To add annotation use : addAnnotation:
read about it here