iOS PencilKit不在PKCanvasView上绘制

Question

在iOS模拟器中，我已经遵循了将PencilKit包含到我的视图控制器中的基本步骤。我在UI中获得了toolKit，但无法绘制。不知道我错过了什么。分享我尝试过的代码。

import UIKit
import PencilKit

class DrawingBoardViewController: UIViewController {

@IBOutlet weak var canvasView: PKCanvasView!

 override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)       
        setupCanvasView()
    }

 func setupCanvasView() {
                
        let toolPicker = PKToolPicker.init()
        toolPicker.setVisible(true, forFirstResponder: canvasView)
        toolPicker.addObserver(canvasView)
        toolPicker.isRulerActive = false
        canvasView.isOpaque = true
        canvasView.becomeFirstResponder()
        canvasView.drawingPolicy = .anyInput
        
    }
}

请让我知道我这里错过了什么..

Answer 1

这应该可以解决您的问题：

import UIKit
import PencilKit

class DrawingBoardViewController: UIViewController {

@IBOutlet weak var canvasView: PKCanvasView!

let toolPicker = PKToolPicker.init()

 override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)       
        setupCanvasView()
    }

 func setupCanvasView() {
                
        toolPicker.setVisible(true, forFirstResponder: canvasView)
        toolPicker.addObserver(canvasView)
        toolPicker.isRulerActive = false
        canvasView.isOpaque = true
        canvasView.becomeFirstResponder()
        canvasView.drawingPolicy = .anyInput
        
    }
}