在Swift中下载文件,通常可以使用URLSession类来实现。下面是一个简单的示例代码,展示了如何使用URLSession下载文件并保存到本地。
import Foundation
func downloadFile(from url: URL, to destination: URL, completion: @escaping (Result<URL, Error>) -> Void) {
let task = URLSession.shared.downloadTask(with: url) { (location, response, error) in
if let error = error {
completion(.failure(error))
return
}
guard let location = location else {
completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "下载失败,未获取到文件位置"])))
return
}
do {
// 确保目标目录存在
try FileManager.default.createDirectories(for: destination.deletingLastPathComponent(), withIntermediateDirectories: true)
// 将下载的文件移动到目标路径
try FileManager.default.moveItem(at: location, to: destination)
completion(.success(destination))
} catch {
completion(.failure(error))
}
}
task.resume()
}
// 使用示例
let fileURL = URL(string: "https://example.com/path/to/file.zip")!
let destinationURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("file.zip")
downloadFile(from: fileURL, to: destinationURL) { result in
switch result {
case .success(let url):
print("文件下载成功,保存路径: \(url)")
case .failure(let error):
print("文件下载失败: \(error.localizedDescription)")
}
}
通过上述代码和解释,你应该能够在Swift中实现文件下载功能,并处理常见的相关问题。
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