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• 首先获取app文件夹：(以下例子都在doucment文件夹下操作)
• 1、创建文件夹
• 2、创建文件，并写入内容
• 3、文件夹/文件 信息
• 4、删除 文件夹/文件
• 5、清空文件夹
• 6、遍历文件夹
• 7、文件写入数据
• 8、读取文件内容
• 9、复制文件
• 10、移动文件
• 11、比较文件

首先获取app文件夹：(以下例子都在doucment文件夹下操作)

let manager = FileManager.default
let urls: [URL] = manager.urls(for: .documentDirectory, in: .userDomainMask)
// .libraryDirectory、.cachesDirectory ...
self.documentURL = urls.first!

1、创建文件夹

let url = self.documentURL.appendingPathComponent("moxiaoyan", isDirectory: true)
var isDirectory: ObjCBool = ObjCBool(false)
let isExist = manager.fileExists(atPath: url.path, isDirectory: &isDirectory)
if !isExist {
  do {
    try manager.createDirectory(at: url, withIntermediateDirectories: true, attributes: nil)
  } catch {
    print("createDirectory error:\(error)")
  }
}

2、创建文件，并写入内容

let url = self.documentURL.appendingPathComponent("moxiaoyan/test1.txt", isDirectory: true) // txt文件会自动创建，只要给个名称就行
let string = "moxiaoyan"
do {
  try string.write(to: url, atomically: true, encoding: .utf8)
  // Data、Array、Dictionary、Image 都可以write
} catch {
  print("write string error:\(error)")
}

3、文件夹/文件 信息

let url = self.documentURL.appendingPathComponent("moxiaoyan", isDirectory: true) // or "moxiaoyan/test1.txt"
// 可读、可写、可执行、可删除
let readable = manager.isReadableFile(atPath: url.path)
let writeable = manager.isWritableFile(atPath: url.path)
let executable = manager.isExecutableFile(atPath: url.path)
let deleteable = manager.isDeletableFile(atPath: url.path)
print("readable:\(readable) writeable:\(writeable) executable:\(executable) deleteable:\(deleteable)")
 
// NSFileCreationDate:创建时间、NSFileSize:文件大小、NSFileType:文件类型...
do {
  let attributes: Dictionary = try manager.attributesOfItem(atPath: url.path)
  print("attributes\(attributes)")
  let fileSize = attributes[FileAttributeKey.size] as! Int
  print("fileSize:\(fileSize)")
} catch {
  print("attributes error: \(error)")
}

4、删除 文件夹/文件

let url = self.documentURL.appendingPathComponent("moxiaoyan", isDirectory: true)
var isDirectory: ObjCBool = ObjCBool(false)
let isExist = manager.fileExists(atPath: url.path, isDirectory: &isDirectory)
if isExist {
  do {
    try manager.removeItem(at: url) // 删除文件
    // try manager.removeItem(atPath: url.path) // 删除文件路径
  } catch {
    print("removeItem error:\(error)")
  }
}

5、清空文件夹

// 删除文件夹里的所有文件，而不删除文件夹
let url = self.documentURL.appendingPathComponent("moxiaoyan", isDirectory: true)
// 方法1：删除，再创建
// self.deleteFile(name)
// self.createFile(name)
 
// 方法2：遍历文件删除
let files = manager.subpaths(atPath: url.path)
for file in files ?? [] {
  do {
    try manager.removeItem(atPath: url.path + "/\(file)") // 需要拼接路径！！
  } catch {
    print("remove item:\(file)\n error:\(error)")
  }
}

6、遍历文件夹

let url = self.documentURL.appendingPathComponent("moxiaoyan", isDirectory: true)
// 1.1 浅遍历：只有 文件夹/文件 名
do {
  let contentsOfDirectory = try manager.contentsOfDirectory(atPath: url.path)
  print("contentsOfDirectory:\(contentsOfDirectory)")
} catch {
  print("1.1 浅遍历 error:\(error)")
}
// 1.2 浅遍历：包含完整路径
do {
  let contentsOfDirectory = try manager.contentsOfDirectory(at: url,
                                                            includingPropertiesForKeys: nil,
                                                            options: .skipsHiddenFiles)
  print("skipsHiddenFiles:\(contentsOfDirectory)")
} catch {
  print("1.2 浅遍历 error:\(error)")
}
 
// 2.1 深度遍历：只有当前文件夹下的路径
let enumberatorAtPath = manager.enumerator(atPath: url.path)
print("2.1 深度遍历：\(enumberatorAtPath?.allObjects)")
// 2.2 深度遍历：包含完整路径
let enumberatorAtURL = manager.enumerator(at: url,
                                          includingPropertiesForKeys: nil,
                                          options: .skipsHiddenFiles,
                                          errorHandler: nil)
print("2.2 深度遍历：\(enumberatorAtURL?.allObjects)")

7、文件写入数据

let url = self.documentURL.appendingPathComponent("moxiaoyan/test1.txt", isDirectory: true)
guard let data = string.data(using: .utf8, allowLossyConversion: true) else {
  return
}
// 1.写在结尾
do {
  let writeHandler = try FileHandle(forWritingTo: url)
  writeHandler.seekToEndOfFile()
  writeHandler.write(data)
} catch {
  print("writeHandler error:\(error)")
}
// 2.从第n个字符开始覆盖
do {
  let writeHandler = try FileHandle(forWritingTo: url)
  do {
    try writeHandler.seek(toOffset: 1)
  } catch {
    print("writeHandler.seek error:\(error)")
  }
  writeHandler.write(data)
} catch {
  print("writeHandler error:\(error)")
}
// 3.只保留前n个字符
do {
  let writeHandler = try FileHandle(forWritingTo: url)
  do {
    try writeHandler.truncate(atOffset: 1)
  } catch {
    print("writeHandler.truncate error:\(error)")
  }
  writeHandler.write(data)
} catch {
  print("writeHandler error:\(error)")
}
// 4.只保留前n个字符:(n超过原字符长度，则并接在结尾)
do {
  let writeHandler = try FileHandle(forWritingTo: url)
  writeHandler.truncateFile(atOffset: 12)
  writeHandler.write(data)
} catch {
  print("writeHandler error:\(error)")
}

8、读取文件内容

let url = self.documentURL.appendingPathComponent("moxiaoyan/test1.txt", isDirectory: true)
// 方法1:
guard let data = manager.contents(atPath: url.path) else {
  return
}
let readString = String(data: data, encoding: .utf8)
print("方法1：\(readString ?? "")")
// 方法2:
guard let readHandler = FileHandle(forReadingAtPath: url.path) else {
  return
}
guard let data2: Data = readHandler.readDataToEndOfFile() else {
  return
}
let readString2 = String(data: data2, encoding: .utf8)
print("方法2：\(readString2 ?? "")")

9、复制文件

let file1 = self.documentURL.appendingPathComponent("moxiaoyan/test1.txt")
let file2 = self.documentURL.appendingPathComponent("moxiaoyan/test2.txt")
do {
  // try manager.copyItem(at: file1, to: file2) // 直接复制文件
  try manager.copyItem(atPath: file1.path, toPath: file2.path) // 复制文件内容
} catch {
  print("copyItem error:\(error)")
}

10、移动文件

let url = self.documentURL.appendingPathComponent(name, isDirectory: true)
let file1 = url.appendingPathComponent(name)
print("文件1:\(file1)")
let file2 = url.appendingPathComponent(to + "/test1.txt")
print("文件2:\(file2)")
do {
  // try manager.moveItem(atPath: file1.path, toPath: file2.path) // 直接拷贝文件
  try manager.moveItem(at: file1, to: file2) // 拷贝文件内容
} catch {
  print("moveItem error:\(error)")
}

11、比较文件

let file1 = self.documentURL.appendingPathComponent(name1)
let file2 = self.documentURL.appendingPathComponent(name2)
// 参数必须的是路径（相同字符串false）
let equal = manager.contentsEqual(atPath: file1.path, andPath: file2.path) 
print("file1:\(file1)")
print("file2:\(file2)")
print("equal:\(equal)")