Question

I am trying to store CGPoints from UITouches in an Array. From reading other threads I have realized that using NSValue seems to be the best way to do this.
Currently I have:

NSMutableArray *dotsArray;
NSValue *pointObj;
UITouch *touch = obj;
CGPoint touchPoint = [touch locationInView:self.view];
// Need to store the CGPoints, can't store directly into an array // as it is a C struct           // so we use NSValue
// CGPoint converted to NSValue
CGPoint point = touchPoint;
pointObj = [NSValue valueWithCGPoint:point];
dotsArray = [NSArray arrayWithObjects:pointObj,nil];
// Print to console the objects in the collection
NSLog(@"array content: %@", dotsArray);
NSLog(@"[dotsArray count] = %i",[dotsArray count]);
// Restore from NSValue to C structures
CGPoint pointRestored = [pointObj CGPointValue];

I want to be able to use:

[dotsArray insertObject:pointObj atIndex:0]; 

in place of

dotsArray = [NSArray arrayWithObjects:pointObj,nil]; 

so that I can increment the placing as I recall the method to store multiple points.

From reading I think this has something to do with the ID type required for the ‘insertObject’, but I don’t fully understand it and am unable to find a solution online.

EDIT: When I use

[dotsArray insertObject:pointObj atIndex:0];

then

NSLog(@"array content: %@", dotsArray);

outputs NULL

Answer 1

Use addObject: method.

[dotsArray addObject:pointObj];

I think it will be helpful to you.