xcode - 保存 PencilKit 图像 – SwiftUI
问题描述
我有一个 SwiftUI 视图来使用 UIViewRepresentable PencilKit 视图捕获用户签名。该视图很好地捕获了签名,但是当我尝试保存签名时,保存的文件是空白/空 PNG 文件。
import PencilKit
struct SignatureUI: View {
let canvasView = PKCanvasView(frame: .init(x: 0, y: 0, width: 400.0, height: 100.0))
let imgRect = CGRect(x: 0, y: 0, width: 400.0, height: 100.0)
let today = Date()
var dateFormatter: DateFormatter {
let formatter = DateFormatter()
formatter.dateStyle = .long
return formatter
}
var body: some View {
VStack {
Text ("Sign here:")
PencilKitRepresentable()
.frame(height: 100.0)
.border(Color.gray, width: 5)
Button(action: {
self.saveSignature()
}) {
Text("Save Signature")
}
}
}
func saveSignature() {
let image = canvasView.drawing.image(from: imgRect, scale: 1.0)
if let data = image.pngData() {
let filename = getDocumentsDirectory().appendingPathComponent("\(self.dateFormatter.string(from: self.today)).png")
try? data.write(to: filename)
print(filename)
}
}
}
struct PencilKitRepresentable : UIViewRepresentable {
func makeUIView(context: Context) -> PKCanvasView {
return PKCanvasView(frame: .init(x: 0, y: 0, width: 400, height: 80));
}
func updateUIView(_ uiView: PKCanvasView, context: Context) {
}
}
解决方案
我认为您在这里使用了两种不同的画布。
尝试这样的事情:
struct PencilKitRepresentable : UIViewRepresentable {
let canvas = PKCanvasView(frame: .init(x: 0, y: 0, width: 400, height: 80))
func makeUIView(context: Context) -> PKCanvasView {
return canvas
}
func updateUIView(_ uiView: PKCanvasView, context: Context) { }
}
和:
struct SignatureUI: View {
let canvasView = PencilKitRepresentable()
let imgRect = CGRect(x: 0, y: 0, width: 400.0, height: 100.0)
var body: some View {
VStack {
Text ("Sign here:")
canvasView.frame(height: 100.0)
.border(Color.gray, width: 5)
Button(action: {
self.saveSignature()
}) {
Text("Save Signature")
}
}
}
func saveSignature() {
let image = canvasView.canvas.drawing.image(from: imgRect, scale: 1.0)
...
}
}
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