iPad Playground有不同的View.Frame

Question

我试图用这段代码在iPad Playgrounds中展示这个简单的ViewController：

import UIKit
import PlaygroundSupport

class MyViewController : UIViewController {
override func viewDidLoad() {
    super.viewDidLoad()
    setupViews()
}

func setupViews() {
    let view1 = UIView(frame: CGRect(x: 0, y: 0, width: view.frame.width/2, height: 100))
    view1.backgroundColor = .red
    view.addSubview(view1)
}
}
// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()

您可以看到，即使它为View1的框架显示view.frame.width / 2，视图仍然如下所示：

怎么了？谢谢。

Answer 1

这是我使用的解决方案。在Swift Playgrounds中，布局是在viewDidLayoutSubview方法中创建的，因此应在那里创建所有帧。

Answer 2

初始化ViewController后，您可以设置首选大小：

import UIKit
import PlaygroundSupport

class VC: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        setupViews()
    }

    func setupViews() {
        let view1 = UIView(frame: CGRect(x: 0, y: 0, width: view.frame.width/2, height: 100))
        view1.backgroundColor = .red
        view.addSubview(view1)
    }
}

let vc = VC()
vc.preferredContentSize = CGSize(width: 768, height: 1024)

PlaygroundPage.current.liveView = vc

Playground with preferredContentSize

Playground without preferredContentSize