如何创建 UnsafeMutablePointer<CGPoint>快速对象 [英] How to create UnsafeMutablePointer<CGPoint> Object in swift
本文介绍了如何创建 UnsafeMutablePointer<CGPoint>快速对象的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我需要调用 UIScrollViewDelegate
方法我不知道如何创建 UnsafeMutablePointer 对象.
I need to call the UIScrollViewDelegate
methods I don't know how to create UnsafeMutablePointer object.
let pointer:UnsafeMutablePointer<CGPoint> = CGPoint(x: 0, y: 1) as! UnsafeMutablePointer<CGPoint>
self.scrollViewWillEndDragging(self.collectionView, withVelocity: CGPoint(x: 0, y: 1), targetContentOffset: pointer)
func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>)
{
//Some code here
}
推荐答案
import Foundation
var point = CGPoint(x: 10.0, y: 20.0)
let p = withUnsafeMutablePointer(&point) { (p) -> UnsafeMutablePointer<CGPoint> in
return p
}
print(p.memory.x, p.memory.y) // 10.0 20.0
point.x = 100.0
print(p.memory.x, p.memory.y) // 100.0 20.0
借助 Swift 的语法糖
with help of Swift's syntactic sugar
import Foundation
var point = CGPoint(x: 10.0, y: 20.0)
let p = withUnsafeMutablePointer(&point) { $0 }
print(p.dynamicType) // UnsafeMutablePointer<CGPoint>
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