how to draw line between two points? - iphone

Question

i want to draw line between two points in my view how it possible.?
Edit:ya thax.i have got solution. Line draw perfectly.I want to draw multiple line with different points.I am using for loop and every rotaion i pass the start and end points.but only last point is drawn.how to solve this problem?

Answer 1

You need to use a few CoreGraphics functions:
// get the current context
CGContextRef context = UIGraphicsGetCurrentContext();
// set the stroke color and width
CGContextSetRGBStrokeColor(context, 0.0, 0.0, 0.0, 1.0);
CGContextSetLineWidth(context, 2.0);
// move to your first point
CGContextMoveToPoint(context, 10.0, 10.0);
// add a line to your second point
CGContextAddLineToPoint(context, 50.0, 10.0);
// tell the context to draw the stroked line
CGContextStrokePath(context);
This example would draw a horizontal white line with a thickness of 2. Apple has some great sample code and tutorials including the QuartzDemo tutorial: http://developer.apple.com/iPhone/library/samplecode/QuartzDemo/index.html.

Answer 2

The QuartzDemo application has great examples of how to use CoreGraphics, including lines and bezier curves. download here
Take a look at QuartzLineDrawing.m in the sample code. You'll be able to find some great examples there :-)

Answer 3

Since this is 09' answers and whatnot I figure I update the link and code here for anyone looking in 11'.
The link for the Quartz Demo is: http://developer.apple.com/library/ios/#samplecode/QuartzDemo/Introduction/Intro.html
and the code I use to draw multiple lines is:
//Drawing lines
// Set the color that we want to use to draw the line
[ [ UIColor brownColor] set];
//Get the current graphics context (pen)
CGContextRef currentContext = UIGraphicsGetCurrentContext();
// Set the width for the line
CGContextSetLineWidth(currentContext,
5.0f);
// Start the line at this point
CGContextMoveToPoint(currentContext,
20.0f,
20.0f);
// And end it at this point
CGContextAddLineToPoint(currentContext,
100.0f,
100.0f);
// Extend the line to another point
CGContextAddLineToPoint(currentContext,
300.0f,
100.0f);
//Use the context's current color to draw the line
CGContextStrokePath(currentContext);
I recommend reading Graphics and Animation on iOS: A Beginner's Guide to Core Graphics and Core Animation by Vandad Nahavandipoor. It's mostly on graphics than animation though. I recommend checking out his videos on animation if your interested. http://www.youtube.com/watch?v=ybMFPB-Gbsw&feature=player_embedded They're called Animations in iOS using Block Objects Part I and II. Supposedly there are supposed to be more videos at some point. But the videos go with the book.
That's it.

Answer 4

func locationManager(manager: CLLocationManager, didUpdateToLocation newLocation: CLLocation, fromLocation oldLocation: CLLocation)
{
let CurrentLogitude = String(format: "%.8f", newLocation.coordinate.longitude)
//print(CurrentLogitude)
let CurrentLatitude = String(format: "%.8f", newLocation.coordinate.latitude)
// print(CurrentLatitude)
//[self.locationManager stopUpdatingLocation];
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError)
{
}
func locationManager(manager: CLLocationManager,
didChangeAuthorizationStatus status: CLAuthorizationStatus)
{
var shouldIAllow = false
var locationStatus :String
switch status
{
case CLAuthorizationStatus.Restricted:
locationStatus = "Restricted Access to location"
case CLAuthorizationStatus.Denied:
locationStatus = "User denied access to location"
case CLAuthorizationStatus.NotDetermined:
locationStatus = "Status not determined"
default:
locationStatus = "Allowed to location Access"
shouldIAllow = true
}
NSNotificationCenter.defaultCenter().postNotificationName("LabelHasbeenUpdated", object: nil)
if (shouldIAllow == true)
{
NSLog("Location to Allowed")
// Start location services
locationManager.startUpdatingLocation()
} else {
NSLog("Denied access: \(locationStatus)")
}
}
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView?
{
let pin = MKAnnotationView(annotation: annotation, reuseIdentifier: "locationpin")
pin.image = UIImage(named: "locationpin.png")
let notationView: UIView = UIView()
notationView.frame = CGRectMake(0, 0, 400, 300)
notationView.backgroundColor = UIColor.grayColor()
pin.leftCalloutAccessoryView = notationView
pin.canShowCallout = true
return pin
}

Answer 5

#pragma mark - Mapview Delegate Method
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
MKPinAnnotationView *pin = (MKPinAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier: #"id"];
if (!pin && ![annotation isKindOfClass:[MKUserLocation class]])
{
pin = [[MKPinAnnotationView alloc] initWithAnnotation: annotation reuseIdentifier: #"id"] ;
pin.pinTintColor=[UIColor blueColor];
pin.canShowCallout = true;
}
else
{
if (pin == nil)
{
pin = [[MKPinAnnotationView alloc] initWithAnnotation: annotation reuseIdentifier: #"id"] ;
}
else
{
pin.annotation = annotation;
}
pin.pinTintColor=[UIColor grayColor];
UIView *notationView=[[UIView alloc]init];
notationView.frame=CGRectMake(0, 0, 320, 300);
notationView.backgroundColor = [UIColor grayColor];
UILabel *lbl=[[UILabel alloc]init];
lbl.frame=CGRectMake(5, 5, 300, 25);
lbl.text=#"Current Location";
lbl.textColor=[UIColor whiteColor];
[notationView addSubview:lbl];
UIImageView *img=[[UIImageView alloc]init];
img.frame=CGRectMake(0, 0, 50,50);
img.image=[UIImage imageNamed:#"ios.png"];
// pin.leftCalloutAccessoryView = notationView;
// pin.rightCalloutAccessoryView = img;
//pin.detailCalloutAccessoryView=customView;
pin.animatesDrop = true;
pin.canShowCallout = true;
}
return pin;
}

Answer 6

-(IBAction)btnRoutePathClicked:(id)sender
{
[self.mapView removeAnnotation:point];
[self.mapView removeOverlay:polyline];
[self.mapView reloadInputViews];
MKCoordinateSpan span = MKCoordinateSpanMake(1.0, 1.0);
MKCoordinateRegion region = MKCoordinateRegionMake(currentLocation.coordinate, span);
[self.mapView setRegion:region];
[self.mapView setCenterCoordinate:currentLocation.coordinate animated:YES];
NSString *baseUrl = [NSString stringWithFormat:#"http://maps.googleapis.com/maps/api/directions/json?origin=%#&destination=%#&sensor=true",[NSString stringWithFormat:#"%f,%f",currentLocation.coordinate.latitude,currentLocation.coordinate.longitude],[NSString stringWithFormat:#"22.45,72.4545"]];
//http://maps.googleapis.com/maps/api/directions/json?origin=51.194400,4.475816&destination=50.941278,6.958281&sensor=true
NSURL *url = [NSURL URLWithString:[baseUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
NSError *error = nil;
NSDictionary *result = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
NSArray *routes = [result objectForKey:#"routes"];
if ([routes count]==0)
{
NSLog(#"Routs:=>%#",routes);
}
else
{
NSDictionary *firstRoute = [routes objectAtIndex:0];
NSDictionary *leg = [[firstRoute objectForKey:#"legs"] objectAtIndex:0];
NSDictionary *end_location = [leg objectForKey:#"end_location"];
double latitudes = [[end_location objectForKey:#"lat"] doubleValue];
double longitudes = [[end_location objectForKey:#"lng"] doubleValue];
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitudes, longitudes);
point = [[MKPointAnnotation alloc] init];
point.coordinate = coordinate;
point.title = [leg objectForKey:#"end_address"];
[self.mapView addAnnotation:point];
NSDictionary *route = [routes lastObject];
if (route)
{
NSString *overviewPolyline = [[route objectForKey: #"overview_polyline"] objectForKey:#"points"];
NSMutableArray *_path = [self decodePolyLine:overviewPolyline];
NSInteger numberOfSteps = _path.count;
CLLocationCoordinate2D coordinates[numberOfSteps];
for (NSInteger index = 0; index < numberOfSteps; index++)
{
CLLocation *location = [_path objectAtIndex:index];
CLLocationCoordinate2D coordinate = location.coordinate;
coordinates[index] = coordinate;
}
polyline = [MKPolyline polylineWithCoordinates:coordinates count:numberOfSteps];
[self.mapView addOverlay:polyline];
}
}
}];
}
-(NSMutableArray *)decodePolyLine:(NSString *)encodedStr
{
NSMutableString *encoded = [[NSMutableString alloc] initWithCapacity:[encodedStr length]];
[encoded appendString:encodedStr];
[encoded replaceOccurrencesOfString:#"\\\\" withString:#"\\"
options:NSLiteralSearch
range:NSMakeRange(0, [encoded length])];
NSInteger len = [encoded length];
NSInteger index = 0;
NSMutableArray *array = [[NSMutableArray alloc] init];
NSInteger lat=0;
NSInteger lng=0;
while (index < len)
{
NSInteger b;
NSInteger shift = 0;
NSInteger result = 0;
do
{
b = [encoded characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
NSInteger dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do
{
b = [encoded characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
NSInteger dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));
lng += dlng;
NSNumber *latitudes = [[NSNumber alloc] initWithFloat:lat * 1e-5];
NSNumber *longitudes = [[NSNumber alloc] initWithFloat:lng * 1e-5];
CLLocation *location = [[CLLocation alloc] initWithLatitude:[latitudes floatValue] longitude:[longitudes floatValue]];
[array addObject:location];
}
return array;
}
- (MKPolylineRenderer *)mapView:(MKMapView *)mapView viewForOverlay:(id)overlay{
MKPolylineRenderer *polylineView = [[MKPolylineRenderer alloc] initWithPolyline:overlay];
polylineView.strokeColor = [UIColor redColor];
polylineView.lineWidth = 4.0;
polylineView.alpha = 0.5;
return polylineView;
}