它比较复杂，待会儿出个入门教程。
第一部分
第二部分
代码 1
import SwiftUI
@main
struct MyApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
代码2
import SwiftUI
struct ContentView: View {
@State var Show = false
@State var Show1 = false
@State var Show2 = true
var body: some View {
VStack {
PenShow(ARshow: Show, showPicker: Show1, Transparent: Show2)
}
}
}
//Button to show PencilKit
struct PenShow: View {
@Environment(\.colorScheme) var colorScheme
@State var ARshow = false
@State private var isViewOffScreen = true
@State var showPicker = false
@State var Transparent = true
func simpleSuccess() {UINotificationFeedbackGenerator().notificationOccurred(.success)}
var body: some View {
Button(action: {self.ARshow.toggle()}){
Image(systemName: "pencil.circle")
.font(.title)
}
.fullScreenCover(isPresented: $ARshow){
ZStack{
VStack{
Text("这是内容，可以对这内容进行标记")
}
VStack{
Button(action: {self.ARshow.toggle(); simpleSuccess()}, label: {
HStack{
Image(systemName: "chevron.backward.circle")
.font(.title)
Spacer()
}
})
.padding()
Spacer()
}
// Pencil
HStack {
Spacer()
VStack {
Button(action: {
isViewOffScreen.toggle()
self.showPicker.toggle()
simpleSuccess()
}, label: {
Image(systemName: isViewOffScreen ? "circle" : "circle")
.font(.title)
})
.padding()
Spacer()
}
}
.overlay(
ZStack {
DrawingView(showPicker: $showPicker)
.frame(maxWidth: .infinity, maxHeight: .infinity)
.background(Transparent ? Color(UIColor.systemBackground) : Color.gray.opacity(0))
.offset(x: isViewOffScreen ? UIScreen.main.bounds.width : 0)
.animation(.easeInOut(duration: 0.5), value: isViewOffScreen)
}
)
VStack {
HStack {
if isViewOffScreen {}else{
Button(action: { Transparent.toggle() }, label: {
Image(systemName: Transparent ? "circle.fill" : "circle")
.font(.title)
})
.background(Color(UIColor.systemBackground))
.cornerRadius(5, antialiased: true)
}
Spacer()
Button(action: {
isViewOffScreen.toggle()
self.showPicker.toggle()
simpleSuccess()
}, label: {
Image(systemName: isViewOffScreen ? "pencil.circle" : "pencil.circle.fill")
.font(.title)
})
}
.padding()
Spacer()
}
}
}
}
}
代码3
import SwiftUI
import PencilKit
struct DrawingView: View {
@Environment(\.undoManager) private var undoManager
@Environment(\.colorScheme) var colorScheme
@State private var canvasView = PKCanvasView()
@State private var toolPicker = PKToolPicker()
@State var image: UIImage?
@State var BackImage: UIImage?
@State var newImage: UIImage?
@State var Share = false
@Binding var showPicker: Bool
func saveImage() -> Void {
let image = canvasView.drawing.image(from: CGRect(x: 0, y: 0, width: 4000, height: 3000), scale: 1.0)
let BackImage = UIImage(named: colorScheme == .light ? "LightLine" : "BlackLine")
UIGraphicsBeginImageContext(CGSize(width: 4000, height: 3000))
BackImage!.draw(in: CGRect(x: 0, y: 0, width: 4000, height: 3000))
image.draw(in: CGRect(x: 0, y: 0, width: 4000, height: 3000))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
self.newImage = newImage
}
var body: some View {
ZStack {
CanvasView(isActive: $showPicker, canvasView: $canvasView, toolPicker: $toolPicker, savedImage: saveImage)
VStack {
HStack(spacing: 15){
Button(action: {self.Share.toggle()}){
Image(systemName: "square.and.arrow.up").font(.title2)
}
.sheet(isPresented: $Share){
ShareSheet(activityItems: [newImage as Any])
.presentationDetents([.large, .medium])
}
Button(action: {undoManager?.undo()}){
Image(systemName: "arrow.uturn.backward").font(.title2)
}
Button(action: {undoManager?.redo()}){
Image(systemName: "arrow.uturn.right").font(.title2)
}
Button(action: {canvasView.drawing = PKDrawing()}){
Image(systemName: "trash").font(.title2)
}
}
.background(Color(UIColor.systemBackground))
.cornerRadius(5, antialiased: true)
Spacer()
}
.padding()
if Share {
ShareSheet(activityItems: [image as Any])
.frame(width: 1, height: 1, alignment: .center)
}
}
}
}
struct CanvasView: UIViewRepresentable {
@Binding var isActive: Bool
@Binding var canvasView: PKCanvasView
@Binding var toolPicker: PKToolPicker
let savedImage: () -> Void
func makeUIView(context: Context) -> PKCanvasView {
canvasView.tool = PKInkingTool(.pen, color: .blue, width: 5)
canvasView.drawingPolicy = .default
canvasView.delegate = context.coordinator //设置委托
canvasView.contentSize = CGSize(width: 4000, height: 3000) //设置内容尺寸
canvasView.showsHorizontalScrollIndicator = false //隐藏水平滚动条
canvasView.showsVerticalScrollIndicator = false //隐藏垂直滚动条
canvasView.backgroundColor = .clear //清除背景
canvasView.becomeFirstResponder() //设置 canvasView 为第一响应视图
toolPicker.setVisible(isActive, forFirstResponder: canvasView) //工具选择器的可见性
toolPicker.addObserver(canvasView) //监听 canvesView 视图
canvasView.isOpaque = true
canvasView.addSubview(UIImageView(image: UIImage(named:"BackLine")))//背景图
return canvasView
}
func updateUIView(_ canvasView: PKCanvasView, context: Context) {
toolPicker.setVisible(isActive, forFirstResponder: canvasView)//隐藏和显示笔
}
func makeCoordinator() -> Coordinator {
return Coordinator(canvasView: $canvasView, savedImage: savedImage)
}
class Coordinator: NSObject, PKCanvasViewDelegate , PKToolPickerObserver{//Save
var canvasView: Binding<PKCanvasView>
let savedImage: () -> Void
init(canvasView: Binding<PKCanvasView>, savedImage: @escaping () -> Void) {
self.canvasView = canvasView
self.savedImage = savedImage
}
func canvasViewDrawingDidChange(_ canvasView: PKCanvasView) {
if !canvasView.drawing.bounds.isEmpty { savedImage() }
}
}
}
struct ShareSheet: UIViewControllerRepresentable {//Share
typealias Callback = (
_ activityType: UIActivity.ActivityType?,
_ completed: Bool,
_ returnedItems: [Any]?,
_ error: Error? ) -> Void
let activityItems: [Any]
let applicationActivities: [UIActivity]? = nil
let excludedActivityTypes: [UIActivity.ActivityType]? = nil
let callback: Callback? = nil
func makeUIViewController(context: Context) -> UIActivityViewController {
let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: applicationActivities)
controller.excludedActivityTypes = excludedActivityTypes
controller.completionWithItemsHandler = callback
return controller
}
func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
}