frame.size.width和frame.width之间的区别 [英] Difference between frame.size.width and frame.width

问题描述

我正在swift中编写一个程序，刚才我注意到我可以直接访问 CGRect 框架的width和height属性而不使用 CGSize 宽度和高度。那就是我现在能够编写这样的代码。

I was writing a program in swift and just now I noticed that I can directly access a CGRect frame's width and height properties directly without using the CGSize width and height. That is I am now able to write a code like this.

@IBOutlet var myView: UIView!

override func viewDidLoad()
{
    super.viewDidLoad()
    var height = myView.frame.height
    var height1 = myView.frame.size.height
}

在Objective C中，当我尝试编写相同的代码时，行 height = view.frame.height 抛出错误。任何人都可以告诉我这两行代码中的差异（如果有的话）。

In Objective C, when I tried to write the same code, the line height = view.frame.height is throwing an error. Can anyone please tell me the difference(if any) in these two lines of code.

推荐答案

我只是看了 CGRect 结构参考。在Swift中，定义了一个扩展名，其成员 height 和 width 。请看下面的代码

I just looked into the CGRect structure reference. In Swift there is an extension defined which have members height and width. Please have a look at the code below

struct CGRect {
var origin: CGPoint
var size: CGSize
}

extension CGRect {
    ...
    var width: CGFloat { get }
    var height: CGFloat { get }
    ...
}

这样你就可以直接获取身高和 width 来自 CGRect 的值。如您所见，这些只是 getters ，因此如果您尝试使用 view.frame.height = someValue <设置这些值，则会出错/ code>

So that you can directly fetch height and width values from a CGRect. As you can see these are only getters, so you will get an error if you try to set these values using view.frame.height = someValue

这篇关于frame.size.width和frame.width之间的区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！