uikit - 从 UIImage 转换为 SwiftUI Image 会产生相同大小的空白图像

Question

我正在尝试转换 UIImage到 SwiftUI Image使用 init(uiImage:)初始化程序。我的 UIImage 本身是从 CIQRCodeGenerator CIFilter 生成的 CIImage 创建的。我在 Xcode 11.1 GM 种子 1 的 Playground 上运行我的代码。这是我的全部代码:

import SwiftUI
import UIKit

func qrCodeImage(for string: String) -> Image? {
  let data = string.data(using: String.Encoding.utf8)
  guard let qrFilter = CIFilter(name: "CIQRCodeGenerator") else { return nil }
  qrFilter.setValue(data, forKey: "inputMessage")

  guard let ciImage = qrFilter.outputImage else { return nil }
  let uiImage = UIImage(ciImage: ciImage)
  let image = Image(uiImage: uiImage)

  return image
}

let image = qrCodeImage(for: "fdsa")

结果如下:



即使我用 CGAffineTransform(scaleX: 10, y: 10) 转换图像，最后生成的 SwiftUI Image 仍然是相同的大小，但是是空白的。

Answer 1

以下解决方案提供于:Generating QR Code with SwiftUI shows empty picture

这是代码:

var ciContext = CIContext()

func qrCodeImage(for string: String) -> Image? {
    let data = string.data(using: String.Encoding.utf8)
    guard let qrFilter = CIFilter(name: "CIQRCodeGenerator") else { return nil }
    qrFilter.setValue(data, forKey: "inputMessage")

    guard let ciImage = qrFilter.outputImage else { return nil }
    let cgImage = ciContext.createCGImage(ciImage, from: ciImage.extent)

    let uiImage = UIImage(cgImage: cgImage!)

    let image = Image(uiImage: uiImage)

    return image
}

 let image = qrCodeImage(for: "fdsa")

结果:

screenshot in swift playground