NSFileManager 唯一文件名

使用NSFileManager唯一文件名的方法

swift
import Foundation
func generateUniqueFileName() -> String? {
    let fileManager = FileManager.default
    let documentsURL = fileManager.urls(for: .documentDirectory, in: .userDomainMask).first
    
    if let documentsURL = documentsURL {
        let uniqueFileName = fileManager.uniqueFileName(for: documentsURL)
        return uniqueFileName
    }
    
    return nil
}
extension FileManager {
    func uniqueFileName(for directory: URL) -> String {
        var isUnique = false
        var uniqueFileName: String = ""
        
        while !isUnique {
            let fileName = UUID().uuidString
            let fileURL = directory.appendingPathComponent(fileName)
            
            if !fileManager.fileExists(atPath: fileURL.path) {
                uniqueFileName = fileName
                isUnique = true
            }
        }
        
        return uniqueFileName
    }
}

swift
import UIKit
func saveImageToUniqueFileName(_ image: UIImage) -> String? {
    guard let data = image.pngData() else {
        return nil
    }
    
    if let uniqueFileName = generateUniqueFileName(),
       let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
        let fileURL = documentsURL.appendingPathComponent(uniqueFileName).appendingPathExtension("png")
        
        do {
            try data.write(to: fileURL)
            return uniqueFileName
        } catch {
            print("Failed to save image: \(error)")
        }
    }
    
    return nil
}