如何在Swift中循环遍历数组的元素

I am new to Swift and wanted to loop through an array of MKMapPoints which I get from an MKPolygon by calling myPoly.points(). However, I am stuck as to how to loop through every element of the C-Array of pointers.

我是Swift的新手，想要遍历一个MKMapPoints数组，我通过调用myPoly.points（）从MKPolygon获取这些数组。但是，我不知道如何循环遍历指针C-Array的每个元素。

 for element in myPointsArray {}

does not work and I don't know how determine the number of elements of this kind of array in Swift. Any ideas? Thanks for your help!

不起作用，我不知道如何确定Swift中这种数组的元素数量。有任何想法吗？谢谢你的帮助！

2 个解决方案

#1

UnsafeBufferPointer presents an unsafe pointer and a count as a collection so you can for..in over it, subscript it safely, pass it to algorithms that work on collections etc:

UnsafeBufferPointer将一个不安全的指针和一个计数作为一个集合呈现，这样你就可以在它上面安全地下标它，将它传递给处理集合的算法等：

for point in UnsafeBufferPointer(start: poly.points(), count: poly.pointCount) {
    println("\(point.x),\(point.y)")
}

#2

You can get the count of points from MKPolygon.pointCount property. And iterate points with traditional for ; ; {} loop:

您可以从MKPolygon.pointCount属性获取点数。并用传统的迭代点; ; {}循环：

let myPointsArray = myPoly.points()

for var i = 0, len = myPoly.pointCount; i < len; i++ {
    let point = myPointsArray[i]
    println(point)
}

#1