CODEWITHSUNDEEP
iphonecocoa-touchios6mapkit
kannan
kannan

Reputation: 421

How to draw a straight line on an iOS map without moving the map using MKmapkit

I want to draw a straight line on an iOS map using MKmapkit without the map moving around.

For example, if the user draws a straight line between two places on the map without removing the finger off the map, I don't want the map view to move around while the user is drawing the line.

I've searched on google, but didn't find an answer/solution.
Please can somebody help me?

Upvotes: 1

Views: 2910

Answers (2)

Anil Kothari
Anil Kothari

Reputation: 7733

Disable the mapkit scroll

_mapView.scrollEnabled=NO;

And then draw line with the help of core graphics

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];


    if (drawImage==nil) {
        drawImage=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
        [self.view addSubview:drawImage];
    }

    lastPoint = [touch locationInView:self.view];
    lastPoint.y -= 20;
    }

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];
    CGPoint currentPoint = [touch locationInView:drawImage];
    currentPoint.y -= 20;

    UIGraphicsBeginImageContext(drawImage.frame.size);
    [drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width,drawImage.frame.size.height)];
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.5, 0.6, 1.0);
    CGContextBeginPath(UIGraphicsGetCurrentContext());
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
    CGContextStrokePath(UIGraphicsGetCurrentContext());
    drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    lastPoint = currentPoint;

}

Upvotes: 2

Siba Prasad Hota
Siba Prasad Hota

Reputation: 4789

You can draw poly line between two or more points/ coordinates.

Here is a question which is answered. Source: Draw a polyline between two coordinates in Xcode

You have to use MKOverlayView like below :

In Interface file

MKPolyline* _routeLine;
MKPolylineView* _routeLineView;

In Implementation file

Store all the coordinates in 

NSMutablrArray *routeLatitudes

then

MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * [routeLatitudes count]); 
for(int idx = 0; idx < [routeLatitudes count]; idx++)
{
    CLLocationCoordinate2D workingCoordinate;       
    workingCoordinate.latitude=[[routeLatitudes objectAtIndex:idx] doubleValue];
    workingCoordinate.longitude=[[routeLongitudes objectAtIndex:idx] doubleValue];  
    MKMapPoint point = MKMapPointForCoordinate(workingCoordinate);
    pointArr[idx] = point;      
}   
// create the polyline based on the array of points. 
routeLine = [MKPolyline polylineWithPoints:pointArr count:[routeLatitudes count]];
[mapViewHome addOverlay:self.routeLine];
free(pointArr);

and Overlay delegate

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
  {
   MKOverlayView* overlayView = nil;

 if(overlay == routeLine)
{
    routeLineView = [[[MKPolylineView alloc] initWithPolyline:self.routeLine]  autorelease];
    routeLineView.fillColor = [UIColor colorWithRed:0.945 green:0.027 blue:0.957  alpha:1];
    routeLineView.strokeColor = [UIColor colorWithRed:0.945 green:0.027 blue:0.957 alpha:1];
    routeLineView.lineWidth = 4;

    overlayView = routeLineView;
}
return overlayView;
}

Upvotes: 0

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