背景图像和使用PencilKit Swiftui绘制的画布 [英] Background Image and canvas with pencilKit Swiftui

问题描述

我正在学习PencilKit.

I'm learning about PencilKit.

我有一个画布，我想设置一个可以在其上绘制的背景图像.

I have a canvas, and I want to set a background image that we can draw on it.

保存画布时，我希望背景图片可见

When I save my canvas, I want my background image to be visible

但是我有一个错误:无法将图像"类型的值转换为预期的参数类型"UIImage"?

But I have an error : Cannot convert value of type 'Image' to expected argument type 'UIImage?'

Image("badmintoncourt")是我的资产中的图像我找不到解决方法，但是可能无法以正确的方式在画布上添加背景图片

Image("badmintoncourt") is an image from my assets I can't find out how to solve it, but I maybe not in the right way to add a background image to my canvas

    struct Home : View {
    @State var canvas = PKCanvasView()
    @Environment(\.undoManager) private var undoManager
    @State var showingAlert = false
    var body: some View{
        
        NavigationView{
            MyCanvas(canvasView: canvas)
                .navigationTitle("Drawing")
                .navigationBarTitleDisplayMode(.inline)
        }
    }
  
}


struct MyCanvas: UIViewRepresentable {
    var canvasView: PKCanvasView
    let picker = PKToolPicker.init()
    
    func makeUIView(context: Context) -> PKCanvasView {
        self.canvasView.tool = PKInkingTool(.pen, color: .black, width: 15)
        self.canvasView.isOpaque = false
        self.canvasView.backgroundColor = UIColor.clear
        self.canvasView.becomeFirstResponder()

        let imageView = Image("badmintoncourt")

        let subView = self.canvasView.subviews[0]
            subView.addSubview(imageView)
            subView.sendSubviewToBack(imageView)
        return canvasView
    }
    
    func updateUIView(_ uiView: PKCanvasView, context: Context) {
        picker.addObserver(canvasView)
        picker.setVisible(true, forFirstResponder: uiView)
        DispatchQueue.main.async {
            uiView.becomeFirstResponder()
        }
    }
}

这是我保存图像的代码:

Edit : Here is my code to save image :

func SaveImage(){
    let image = canvas.drawing.image(from: canvas.drawing.bounds, scale: 1)
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}

推荐答案

Image 不是 UIView ，您必须使用 UIImageView 在这种情况下

The Image is not a UIView, you have to use UIImageView for this case

    let imageView = UIImageView(image: UIImage(named: "badmintoncourt"))

    let subView = self.canvasView.subviews[0]
        subView.addSubview(imageView)
        subView.sendSubviewToBack(imageView)

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