在运行时访问UIView宽度 [英] Access UIView width at runtime

问题描述

在Swift中，我如何获得在运行时使用自动布局约束以编程方式创建的UIView的宽度（或高度）？

In Swift, how do I get the width (or height) at runtime, of a UIView that's created programmatically using auto layout constraints?

我试过 view1.frame.size.width 和 view1.frame.width ，但都返回 0 。

我一直关注 MakeAppPie 并添加 view1.layer.cornerRadius = view1.bounds.width / 2 如下所示，但这没有效果，所以我在 view1.bounds.width 上做了一个po 0 ：

I've been following an auto layout tutorial by MakeAppPie and added view1.layer.cornerRadius = view1.bounds.width/2 as below, but this had no effect, so I did a po on view1.bounds.width and got 0:

class ViewController: UIViewController {

func makeLayout() {

    //Make a view
    let view1 = UIView()
    view1.setTranslatesAutoresizingMaskIntoConstraints(false)
    view1.backgroundColor = UIColor.redColor()


    //Make a second view
    let view2 = UIView()
    view2.setTranslatesAutoresizingMaskIntoConstraints(false)
    view2.backgroundColor = UIColor(red: 0.75, green: 0.75, blue: 0.1, alpha: 1.0)

    //Add the views
    view.addSubview(view1)
    view.addSubview(view2)


    //--------------- constraints

    //make dictionary for views
    let viewsDictionary = ["view1":view1,"view2":view2]

    //sizing constraints
    //view1
    let view1_constraint_H:Array = NSLayoutConstraint.constraintsWithVisualFormat("H:[view1(>=50)]", options: NSLayoutFormatOptions(0), metrics: nil, views: viewsDictionary)
    let view1_constraint_V:Array = NSLayoutConstraint.constraintsWithVisualFormat("V:[view1(50)]", options: NSLayoutFormatOptions(0), metrics: nil, views: viewsDictionary)

    view1.addConstraints(view1_constraint_H)
    view1.addConstraints(view1_constraint_V)

    //view2
    let view2_constraint_H:NSArray = NSLayoutConstraint.constraintsWithVisualFormat("H:[view2(50)]", options: NSLayoutFormatOptions(0), metrics: nil, views: viewsDictionary)
    let view2_constraint_V:NSArray = NSLayoutConstraint.constraintsWithVisualFormat("V:[view2(>=40)]", options: NSLayoutFormatOptions(0), metrics: nil, views: viewsDictionary)

    view2.addConstraints(view2_constraint_H)
    view2.addConstraints(view2_constraint_V)

    //position constraints

    //views
    let view_constraint_H:NSArray = NSLayoutConstraint.constraintsWithVisualFormat("H:|-100-[view2]", options: NSLayoutFormatOptions(0), metrics: nil, views: viewsDictionary)
    let view_constraint_V:NSArray = NSLayoutConstraint.constraintsWithVisualFormat("V:|-136-[view1]-100-[view2]-100-|", options: NSLayoutFormatOptions.AlignAllTrailing, metrics: nil, views: viewsDictionary)

    view.addConstraints(view_constraint_H)
    view.addConstraints(view_constraint_V)

    view1.layer.cornerRadius = view1.bounds.width/2

    }

override func viewDidLoad() {
    super.viewDidLoad()

    func supportedInterfaceOrientations() -> Int {
        return Int(UIInterfaceOrientationMask.All.rawValue)

    }

    // Do any additional setup after loading the view, typically from a nib.

    view.backgroundColor = UIColor(red: 0.9, green: 0.9, blue: 1, alpha: 1.0)
    makeLayout()

    }
}

推荐答案

添加此项并且你很高兴：

Add this and you are good to go:

override func viewDidLayoutSubviews() {
        println(self.view1.frame.size)
    }

您可以随意查看宽度或高度。

you can look at width or height as you please.

这篇关于在运行时访问UIView宽度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！