更新时间:2022-11-19 17:26:45
这是 PointZeroTwo 在 Swift 3.0 中的答案的更新,有一个快速说明 - 在使用简单文件路径的操场测试中有效,但在我的实际应用程序中我需要使用 .documentDirectory 构建 URL(或您选择用于读取和写入的目录 - 确保它在整个应用程序中保持一致):
Here's an update for PointZeroTwo's answer in Swift 3.0, with one quick note - in the playground testing using a simple filepath works, but in my actual app I needed to build the URL using .documentDirectory (or which ever directory you chose to use for reading and writing - make sure it's consistent throughout your app):
extension String {
func appendLineToURL(fileURL: URL) throws {
try (self + "\n").appendToURL(fileURL: fileURL)
}
func appendToURL(fileURL: URL) throws {
let data = self.data(using: String.Encoding.utf8)!
try data.append(fileURL: fileURL)
}
}
extension Data {
func append(fileURL: URL) throws {
if let fileHandle = FileHandle(forWritingAtPath: fileURL.path) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
}
else {
try write(to: fileURL, options: .atomic)
}
}
}
//test
do {
let dir: URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last! as URL
let url = dir.appendingPathComponent("logFile.txt")
try "Test \(Date())".appendLineToURL(fileURL: url as URL)
let result = try String(contentsOf: url as URL, encoding: String.Encoding.utf8)
}
catch {
print("Could not write to file")
}
感谢 PointZeroTwo.
Thanks PointZeroTwo.