override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .gray
view.insetsLayoutMarginsFromSafeArea = false
setupCanvasView()
setupToolPicker()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
// 确保画布成为第一响应者以显示工具栏
canvasView.becomeFirstResponder()
}
func setupCanvasView() {
canvasView.frame = view.bounds
canvasView.delegate = self
canvasView.insetsLayoutMarginsFromSafeArea = false
// 设置画布属性以支持绘画
canvasView.alwaysBounceVertical = true
canvasView.alwaysBounceHorizontal = true
canvasView.isScrollEnabled = true
canvasView.showsVerticalScrollIndicator = true
canvasView.showsHorizontalScrollIndicator = true
canvasView.contentSize = CGSize(width: 500,height: 500)
// 启用绘画功能
canvasView.drawingPolicy = .anyInput // 支持手指和 Apple Pencil
view.addSubview(canvasView)
}
AS THE CODE ABOVE,WHEN I DRAW ON THE CANVAS,THE BACKGROUND CHANGE ITS COLOR TO WHITE.WHY?
!
Topic:
UI Frameworks
SubTopic:
UIKit