Swift – 文件及文件夹操作大全

注：代码已升级至Swift4

iOS开发经常会遇到读文件，写文件等，对文件和文件夹的操作，这时就可以使用FileManager，FileHandle等类来实现。

遍历一个目录下的所有文件

假设用户文档下有如下文件和文件夹：test1.txt、fold1/test2.txt

（1）首先我们获取用户文档目录路径

let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in: .userDomainMask)
let url = urlForDocument[0] as URL
print(url)

（2）对指定路径执行浅搜索，返回指定目录路径下的文件、子目录及符号链接的列表

let contentsOfPath = try? manager.contentsOfDirectory(atPath: url.path)
print("contentsOfPath: \(contentsOfPath)")

（3）类似上面的，对指定路径执行浅搜索，返回指定目录路径下的文件、子目录及符号链接的列表

let contentsOfURL = try? manager.contentsOfDirectory(at: url,
                        includingPropertiesForKeys: nil, options: .skipsHiddenFiles)
print("contentsOfURL: \(contentsOfURL)")

（4）深度遍历，会递归遍历子文件夹（但不会递归符号链接）

let enumeratorAtPath = manager.enumerator(atPath: url.path)
print("enumeratorAtPath: \(enumeratorAtPath?.allObjects)")

（5）类似上面的，深度遍历，会递归遍历子文件夹（但不会递归符号链接）

let enumeratorAtURL = manager.enumerator(at: url, includingPropertiesForKeys: nil,
                                         options: .skipsHiddenFiles, errorHandler:nil)
print("enumeratorAtURL: \(enumeratorAtURL?.allObjects)")

（6）深度遍历，会递归遍历子文件夹（包括符号链接，所以要求性能的话用enumeratorAtPath）

let subPaths = manager.subpaths(atPath: url.path)
print("subPaths: \(subPaths)")

判断文件或文件夹是否存在

let fileManager = FileManager.default
let filePath:String = NSHomeDirectory() + "/Documents/appblog.txt"
let exist = fileManager.fileExists(atPath: filePath)

创建文件夹

方式1：

let myDirectory:String = NSHomeDirectory() + "/Documents/myFolder/Files"
let fileManager = FileManager.default

//withIntermediateDirectories为ture表示路径中间如果有不存在的文件夹都会创建
try! fileManager.createDirectory(atPath: myDirectory,
                        withIntermediateDirectories: true, attributes: nil)

方式2：

func createFolder(name:String,baseUrl:NSURL) {
    let manager = FileManager.default
    let folder = baseUrl.appendingPathComponent(name, isDirectory: true)
    print("文件夹: \(folder)")
    let exist = manager.fileExists(atPath: folder!.path)
    if !exist {
        try! manager.createDirectory(at: folder!, withIntermediateDirectories: true,
                                    attributes: nil)
    }
}

//在文档目录下新建folder目录
let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in: .userDomainMask)
let url = urlForDocument[0] as NSURL
createFolder(name: "folder", baseUrl: url)

将对象写入文件

可以通过write(to:)方法，可以创建文件并将对象写入，对象包括String，NSString，UIImage，NSArray，NSDictionary等。

（1）把String保存到文件

let filePath:String = NSHomeDirectory() + "/Documents/appblog.txt"
let info = "欢迎来到AppBlog.CN"
try! info.write(toFile: filePath, atomically: true, encoding: String.Encoding.utf8)

（2）把图片保存到文件路径下

let filePath = NSHomeDirectory() + "/Documents/appblog.png"
let image = UIImage(named: "apple.png")
let data:Data = UIImagePNGRepresentation(image!)!
try? data.write(to: URL(fileURLWithPath: filePath))

（3）把NSArray保存到文件路径下

let array = NSArray(objects: "aaa","bbb","ccc")
let filePath:String = NSHomeDirectory() + "/Documents/array.plist"
array.write(toFile: filePath, atomically: true)

（4）把NSDictionary保存到文件路径下

let dictionary:NSDictionary = ["Gold": "1st Place", "Silver": "2nd Place"]
let filePath:String = NSHomeDirectory() + "/Documents/dictionary.plist"
dictionary.write(toFile: filePath, atomically: true)

创建文件

func createFile(name:String, fileBaseUrl:URL) {
    let manager = FileManager.default

    let file = fileBaseUrl.appendingPathComponent(name)
    print("文件: \(file)")
    let exist = manager.fileExists(atPath: file.path)
    if !exist {
        let data = Data(base64Encoded:"aGVsbG8gd29ybGQ=" ,options:.ignoreUnknownCharacters)
        let createSuccess = manager.createFile(atPath: file.path,contents:data,attributes:nil)
        print("文件创建结果: \(createSuccess)")
    }
}

//在文档目录下新建test.txt文件
let manager = FileManager.default
let urlForDocument = manager.urls( for: .documentDirectory,
                                   in:.userDomainMask)
let url = urlForDocument[0]
createFile(name:"test.txt", fileBaseUrl: url)
//createFile(name: "folder/new.txt", fileBaseUrl: url)

复制文件

（1）方法1

let fileManager = FileManager.default
let homeDirectory = NSHomeDirectory()
let srcUrl = homeDirectory + "/Documents/appblog.txt"
let toUrl = homeDirectory + "/Documents/copyed.txt"
try! fileManager.copyItem(atPath: srcUrl, toPath: toUrl)

（2）方法2

// 定位到用户文档目录
let manager = FileManager.default
let urlForDocument = manager.urls( for:.documentDirectory, in:.userDomainMask)
let url = urlForDocument[0]

// 将test.txt文件拷贝到文档目录根目录下的copyed.txt文件
let srcUrl = url.appendingPathComponent("test.txt")
let toUrl = url.appendingPathComponent("copyed.txt")

try! manager.copyItem(at: srcUrl, to: toUrl)

移动文件

（1）方法1

let fileManager = FileManager.default
let homeDirectory = NSHomeDirectory()
let srcUrl = homeDirectory + "/Documents/appblog.txt"
let toUrl = homeDirectory + "/Documents/moved/appblog.txt"
try! fileManager.moveItem(atPath: srcUrl, toPath: toUrl)

（2）方法2

// 定位到用户文档目录
let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in:.userDomainMask)
let url = urlForDocument[0]

let srcUrl = url.appendingPathComponent("test.txt")
let toUrl = url.appendingPathComponent("copyed.txt")
// 移动srcUrl中的文件（test.txt）到toUrl中（copyed.txt）
try! manager.moveItem(at: srcUrl, to: toUrl)

删除文件

（1）方法1

let fileManager = FileManager.default
let homeDirectory = NSHomeDirectory()
let srcUrl = homeDirectory + "/Documents/appblog.txt"
try! fileManager.removeItem(atPath: srcUrl)

（2）方法2

// 定位到用户文档目录
let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in:.userDomainMask)
let url = urlForDocument[0]

let toUrl = url.appendingPathComponent("copyed.txt")
// 删除文档根目录下的toUrl路径的文件（copyed.txt文件）
try! manager.removeItem(at: toUrl)

删除目录下所有的文件

（1）方法1：获取所有文件，然后遍历删除

let fileManager = FileManager.default
let myDirectory = NSHomeDirectory() + "/Documents/Files"
let fileArray = fileManager.subpaths(atPath: myDirectory)
for fn in fileArray!{
    try! fileManager.removeItem(atPath: myDirectory + "/\(fn)")
}

（2）方法2：删除目录后重新创建该目录

let fileManager = FileManager.default
let myDirectory = NSHomeDirectory() + "/Documents/Files"
try! fileManager.removeItem(atPath: myDirectory)
try! fileManager.createDirectory(atPath: myDirectory, withIntermediateDirectories: true,
                                attributes: nil)

读取文件

let manager = FileManager.default
let urlsForDocDirectory = manager.urls(for: .documentDirectory, in:.userDomainMask)
let docPath = urlsForDocDirectory[0]
let file = docPath.appendingPathComponent("test.txt")

//方法1
let readHandler = try! FileHandle(forReadingFrom:file)
let data = readHandler.readDataToEndOfFile()
let readString = String(data: data, encoding: String.Encoding.utf8)
print("文件内容: \(readString)")

//方法2
let data2 = manager.contents(atPath: file.path)
let readString2 = String(data: data2!, encoding: String.Encoding.utf8)
print("文件内容: \(readString2)")

在任意位置写入数据

let manager = FileManager.default
let urlsForDocDirectory = manager.urls(for:.documentDirectory, in:.userDomainMask)
let docPath = urlsForDocDirectory[0]
let file = docPath.appendingPathComponent("test.txt")

let string = "添加一些文字到文件末尾"
let appendedData = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
let writeHandler = try? FileHandle(forWritingTo:file)
writeHandler!.seekToEndOfFile()
writeHandler!.write(appendedData!)

文件权限判断

let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in:.userDomainMask)
let docPath = urlForDocument[0]
let file = docPath.appendingPathComponent("test.txt")

let readable = manager.isReadableFile(atPath: file.path)
print("可读: \(readable)")
let writeable = manager.isWritableFile(atPath: file.path)
print("可写: \(writeable)")
let executable = manager.isExecutableFile(atPath: file.path)
print("可执行: \(executable)")
let deleteable = manager.isDeletableFile(atPath: file.path)
print("可删除: \(deleteable)")

获取文件属性

创建时间，修改时间，文件大小，文件类型等信息

let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in:.userDomainMask)
let docPath = urlForDocument[0]
let file = docPath.appendingPathComponent("test.txt")

let attributes = try? manager.attributesOfItem(atPath: file.path) //结果为Dictionary类型
print("attributes: \(attributes!)")

从 attributes 中获取具体的属性：

print("创建时间：\(attributes![FileAttributeKey.creationDate]!)")
print("修改时间：\(attributes![FileAttributeKey.modificationDate]!)")
print("文件大小：\(attributes![FileAttributeKey.size]!)")

文件/文件夹比较

let manager = FileManager.default
let urlForDocument = manager.urls(for: .documentDirectory, in:.userDomainMask)
let docPath = urlForDocument[0]
let contents = try! manager.contentsOfDirectory(atPath: docPath.path)

//下面比较用户文档中前面两个文件是否内容相同（该方法也可以用来比较目录）
let count = contents.count
if count > 1 {
    let path1 = docPath.path + "/" + (contents[0] as String)
    let path2 = docPath.path + "/" + (contents[1] as String)
    let equal = manager.contentsEqual(atPath: path1, andPath:path2)
    print("path1：\(path1)")
    print("path2：\(path2)")
    print("比较结果： \(equal)")
}