NSData 和 UIImage

如何使用 NSData 和 UIImage 进行数据处理和图像操作

swift
let str = "Hello, World!"
let data = str.data(using: .utf8)

swift
if let url = Bundle.main.url(forResource: "file", withExtension: "txt") {
    do {
        let data = try Data(contentsOf: url)
    } catch {
        print("读取文件失败：\(error)")
    }
}

swift
let data = Data()
if let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first?.appendingPathComponent("file.txt") {
    do {
        try data.write(to: url)
    } catch {
        print("写入文件失败：\(error)")
    }
}

swift
let image = UIImage(named: "image.png")

swift
if let url = URL(string: "https://example.com/image.png") {
    if let data = try? Data(contentsOf: url) {
        let image = UIImage(data: data)
    }
}

swift
let size = CGSize(width: 100, height: 100)
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
image.draw(in: CGRect(origin: .zero, size: size))
let resizedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

swift
guard let ciImage = CIImage(image: image) else { return }
let filter = CIFilter(name: "CIPhotoEffectMono")
filter?.setValue(ciImage, forKey: kCIInputImageKey)
if let outputImage = filter?.outputImage {
    let context = CIContext(options: nil)
    let cgImage = context.createCGImage(outputImage, from: outputImage.extent)
    let filteredImage = UIImage(cgImage: cgImage)
}