CLLocationCoordinate2D不知道数组中有多少个？

Question

我需要使用以下内容构建一个数组:

CLLocationCoordinate2D  points[4];


    points[0] = CLLocationCoordinate2DMake(41.000512, -109.050116);

    points[1] = CLLocationCoordinate2DMake(41.002371, -102.052066);

    points[2] = CLLocationCoordinate2DMake(36.993076, -102.041981);

    points[3] = CLLocationCoordinate2DMake(36.99892, -109.045267);

问题是,我永远不会知道数组中有多少项,所以我可以指定计数.有没有办法创建一个CLLocationCoordinate2D数组,只是插入新的坐标而不知道最终的总数是多少？

编辑:我的最终目标是使用坐标来制作MKPolyline,使用需要CLLocationCoordinate2D数组的polylineWithCoordinates方法.

Answer 1

// unpacking an array of NSValues into memory
CLLocationCoordinate2D *points = malloc([mutablePoints count] * sizeof(CLLocationCoordinate2D));
for(int i = 0; i < [mutablePoints count]; i++) {
    [[mutablePoints objectAtIndex:i] getValue:(points + i)];
}

MKPolyline *myPolyline = [MKPolyline polylineWithCoordinates:points count:[mutablePoints count]];
free(points);