How can I add CGPoint objects to an NSArray the easy way?

问题

I have about 50 CGPoint objects that describe something like a "path", and I want to add them to an NSArray. It's going to be a method that will just return the corresponding CGPoint for an given index. I don't want to create 50 variables like p1 = ...; p2 = ..., and so on. Is there an easy way that would let me to define those points "instantly" when initializing the NSArray with objects?

回答1:

With UIKit Apple added support for CGPoint to NSValue, so you can do:

NSArray *points = [NSArray arrayWithObjects:
                     [NSValue valueWithCGPoint:CGPointMake(5.5, 6.6)],
                     [NSValue valueWithCGPoint:CGPointMake(7.7, 8.8)],
                     nil];

List as many [NSValue] instances as you have CGPoint, and end the list in nil. All objects in this structure are auto-released.

On the flip side, when you're pulling the values out of the array:

NSValue *val = [points objectAtIndex:0];
CGPoint p = [val CGPointValue];

回答2:

I use this:

Create array:

NSArray *myArray = @[[NSValue valueWithCGPoint:CGPointMake(30.0, 150.0)],[NSValue valueWithCGPoint:CGPointMake(41.67, 145.19)]];

Get 1st CGPoint object:

CGPoint myPoint = [myArray[0] CGPointValue];

回答3:

You can also write this in a minimal form of:

CGPoint myArray[] = { CGPointMake(5.5, 6.6), CGPointMake(7.7, 8.8) };

CGPoint p2 = myArray[1];

回答4:

Have you taken a look at CFMutableArray? That might work better for you.

来源：https://stackoverflow.com/questions/899600/how-can-i-add-cgpoint-objects-to-an-nsarray-the-easy-way