UIImage:调整大小,然后裁剪

import UIKit

extension UIImage {
    func resize(to newSize: CGSize) -> UIImage? {
        let renderer = UIGraphicsImageRenderer(size: newSize)
        return renderer.image { _ in
            draw(in: CGRect(origin: .zero, size: newSize))
        }
    }
    
    func crop(to rect: CGRect) -> UIImage? {
        guard let cgImage = cgImage?.cropping(to: rect) else { return nil }
        return UIImage(cgImage: cgImage)
    }
}

let originalImage = UIImage(named: "example.jpg")
let newSize = CGSize(width: 100, height: 100)

// 调整大小
if let resizedImage = originalImage?.resize(to: newSize) {
    // 使用调整后的图片
}

// 裁剪图片
let cropRect = CGRect(x: 0, y: 0, width: 50, height: 50)
if let croppedImage = originalImage?.crop(to: cropRect) {
    // 使用裁剪后的图片
}