swift playground UITextField spawns keyboard that is too big

问题

Swift in playground on Mac OS. When the user clicks in a UItextfield, a keyboard spawns but it is very large compared to the view and only the first few keys are available.

minimal example:

import UIKit
import PlaygroundSupport

class TesterViewController : UIViewController {
var testTextField : UITextField!
override func loadView() {
    let view = UIView()
    view.backgroundColor = .white

    testTextField = UITextField()
    testTextField.borderStyle = .roundedRect
    testTextField.text = ""
    view.addSubview(testTextField)
    testTextField.translatesAutoresizingMaskIntoConstraints = false

    NSLayoutConstraint.activate([
        testTextField.topAnchor.constraint(equalTo: view.topAnchor, constant: 20),
        testTextField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
        ])

    self.view = view
    }
}
PlaygroundPage.current.liveView = TesterViewController()

screenshot

回答1:

I face the same issue. It seems as if Playground has a hard-coded screen size of 768x1024 (run UIScreen.main.bounds in the Playground) and shows the keyboard according to this size, independently of the live view's actual size.

The best workaround I came up with is to increase the size of the view controller so that it matches the keyboard:

let vc = TesterViewController()
vc.preferredContentSize = vc.view.frame.size // or a custom CGSize
PlaygroundPage.current.liveView = vc

Of course this makes the view larger than you might want it to be, so I only use this workaround when I really have to access the on-screen keyboard for testing.

回答2:

Instead this line

PlaygroundPage.current.liveView = MyViewController()

Write this

let window = UIWindow(frame: CGRect(x: 0,
                                    y: 0,
                                    width: 768,
                                    height: 1024))
let viewController = MyViewController()
window.rootViewController = viewController
window.makeKeyAndVisible()

PlaygroundPage.current.liveView = window

It works in Xcode 11

来源：https://stackoverflow.com/questions/46867712/swift-playground-uitextfield-spawns-keyboard-that-is-too-big

标签

keyboard

uitextfield

swift-playground