DidDiscoverPeripheral delegate method is not called - ios

Question

I am working with iphone5,and scanning for the device with the UUID.and i want to get list of available bluetooth device in my apps,but didDiscoverPeriphral delegate method is not call. here i give my code.
- (id)init
{
NSLog(#"hello init");
if ((self = [super init]))
{
CM = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_main_queue()];
}
return self;
}
- (void)viewDidLoad
{ CM = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_main_queue()];
isOn=NO;
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (int) scanForPeripherals
{
if (self->CM.state != CBCentralManagerStatePoweredOn)
{
NSLog(#"CoreBluetooth is %s",[self centralManagerStateToString:self->CM.state]);
return -1;
}
[self->CM scanForPeripheralsWithServices:[NSArray arrayWithObject:[CBUUID UUIDWithString:#"180D"]] options:#{CBCentralManagerScanOptionAllowDuplicatesKey: #YES}];
return 0;
}
- (const char *) centralManagerStateToString: (int)state
{
switch(state)
{
case CBCentralManagerStateUnknown:
return "State unknown (CBCentralManagerStateUnknown)";
case CBCentralManagerStateResetting:
return "State resetting (CBCentralManagerStateUnknown)";
case CBCentralManagerStateUnsupported:
return "State BLE unsupported (CBCentralManagerStateResetting)";
case CBCentralManagerStateUnauthorized:
return "State unauthorized (CBCentralManagerStateUnauthorized)";
case CBCentralManagerStatePoweredOff:
return "State BLE powered off (CBCentralManagerStatePoweredOff)";
case CBCentralManagerStatePoweredOn:
return "State powered up and ready (CBCentralManagerStatePoweredOn)";
default:
return "State unknown";
}
return "Unknown state";
}
- (void) connectPeripheral:(CBPeripheral *)peripheral {
printf("Connecting to peripheral with UUID : %s\r\n",[self UUIDToString:peripheral.UUID]);
self->activePeripheral = peripheral;
self->activePeripheral.delegate = self;
[self->CM connectPeripheral:self->activePeripheral options:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:CBConnectPeripheralOptionNotifyOnDisconnectionKey]];
NSLog(#"peripheral :%#",peripheral);
}
-(const char *) UUIDToString:(CFUUIDRef)UUID
{
if (!UUID)
return "NULL";
CFStringRef s = CFUUIDCreateString(NULL, UUID);
return CFStringGetCStringPtr(s, 0);
}
#pragma mark -Central manager delegate method
- (void)centralManagerDidUpdateState:(CBCentralManager *)central
{
NSLog(#"hits it");
if (central.state != CBCentralManagerStatePoweredOn) {
return;
}
isOn=YES;
}
- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{
NSLog(#"Received periferal :%#",peripheral);
NSLog(#"Ad data :%#",advertisementData);
}
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
{
NSLog(#"Connected peripheral %#",peripheral);
}
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
NSLog(#"Error occured :%#",[error localizedDescription]);
}
- (IBAction)scanDevices:(id)sender {
//isOn=YES;
if (isOn) {
[self scanForPeripherals];
}
}
thanks...