如何添加CGPoint对象到NSArray的容易的方法？ [英] How can I add CGPoint objects to an NSArray the easy way?

问题描述

我有大约50个CGPoint对象，描述类似路径的东西，我想将它们添加到NSArray。它将是一个方法，将返回给定索引的相应的CGPoint。我不想创建50个变量，如p1 = ...; p2 = ...，等等。有没有一个简单的方法，让我在初始化NSArray与对象时定义这些点？

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?

推荐答案

code> UIKit 苹果添加了对CGPoint支持 NSValue ，所以你可以这样做：

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];

列出与您拥有CGPoint一样多的[NSValue]实例，并以nil结束列表。

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

另一方面，当你从数组中取出数值时：

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

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

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