iOS开发——Swift篇&文件，文件夹操作

2023-07-27 22:27:22

文件，文件夹操作

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NSFileManager，NSFileHandle等类来实现。

下面总结了各种常用的操作：

1，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]
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil

 //（1）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 = manager.contentsOfDirectoryAtPath(url.path!, error: error)
 //contentsOfPath：Optional([fold1, test1.txt])
 println("contentsOfPath: \(contentsOfPath)")  

 //（2）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 = manager.contentsOfDirectoryAtURL(url, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, error: error);
 //contentsOfURL：Optional([file://Users/.../Application/.../Documents/fold1/,
 // file://Users/.../Application/.../Documents/test1.txt])
 println("contentsOfURL: \(contentsOfURL)") 

 //（3）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.enumeratorAtPath(url.path!)
 //enumeratorAtPath：Optional([fold1, fold1/test2.txt, test1.txt])
 println("enumeratorAtPath: \(enumeratorAtPath?.allObjects)")  

 //（4）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.enumeratorAtURL(url, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, errorHandler:nil)
 //contentsOfURL：Optional([file://Users/.../Application/.../Documents/fold1/,
 // file://Users/.../Application/.../Documents/fold1/test2.txt,
 // file://Users/.../Application/.../Documents/test1.txt])
 println("enumeratorAtURL: \(enumeratorAtURL?.allObjects)")

 //（5）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.subpathsAtPath(url.path!)
 //subPaths：Optional([fold1, fold1/test2.txt, test1.txt])
 println("subPaths: \(subPaths)")

2，判断文件或文件夹是否存在

let fileManager = NSFileManager.defaultManager()
let filePath:String = NSHomeDirectory() + "/Documents/hangge.txt"
var exist = fileManager.fileExistsAtPath(filePath)

3，创建文件夹

方式1：

 let myDirectory:String = NSHomeDirectory() + "/Documents/myFolder/Files"
 let fileManager = NSFileManager.defaultManager()
 var error:NSErrorPointer = nil
 //withIntermediateDirectories为ture表示路径中间如果有不存在的文件夹都会创建
 var isSuccess:Bool = fileManager.createDirectoryAtPath(myDirectory,
     withIntermediateDirectories: true, attributes: nil, error: error)

方式2：

 func createFolder(name:String,baseUrl:NSURL){
     let manager = NSFileManager.defaultManager()
     var error:NSErrorPointer = nil
     let folder = baseUrl.URLByAppendingPathComponent(name, isDirectory: true)
     println("文件夹: \(folder)")
     let exist = manager.fileExistsAtPath(folder.path!)
     if !exist {
         let createSuccess = manager.createDirectoryAtURL(folder, withIntermediateDirectories: true, attributes: nil, error: error)
         println("文件夹创建结果: \(createSuccess)")
     }
 }

 //在文档目录下新建folder目录
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil
 createFolder("folder", baseUrl: url)

4，将对象写入文件
可以通过writeToFile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/hangge.txt"
 var error:NSErrorPointer = nil
 var info = "欢迎来到hange.com"
 info.writeToFile(filePath, atomically: true, encoding: NSUTF8StringEncoding, error: error)

（2）把图片保存到文件路径下

 let filePath:String = NSHomeDirectory() + "/Documents/hangge.png"
 var image = UIImage(named: "apple.png")
 var data:NSData = UIImagePNGRepresentation(image)
 data.writeToFile(filePath, atomically: true)

（3）把NSArray保存到文件路径下

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

（4）把NSDictionary保存到文件路径下

 var dictionary = NSDictionary(objects: ["], forKeys: ["aaa","bbb"])
 let filePath:String = NSHomeDirectory() + "/Documents/dictionary.plist"
 dictionary.writeToFile(filePath, atomically: true)

5，创建文件

 func createFile(name:String,fileBaseUrl:NSURL){
     let manager = NSFileManager.defaultManager()
     var error:NSErrorPointer = nil

     let file = fileBaseUrl.URLByAppendingPathComponent(name)
     println("文件: \(file)")
     let exist = manager.fileExistsAtPath(file.path!)
     if !exist {
         let data = NSData(base64EncodedString:"aGVsbG8gd29ybGQ=",options:.IgnoreUnknownCharacters)
         let createSuccess = manager.createFileAtPath(file.path!,contents:data,attributes:nil)
         println("文件创建结果: \(createSuccess)")
     }
 }

 //在文档目录下新建test.txt文件
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil
 createFile("test.txt", fileBaseUrl: url)
 //createFile("folder/new.txt", fileBaseUrl: url)

6，复制文件

（1）方法1

 let fileManager = NSFileManager.defaultManager()
 let homeDirectory = NSHomeDirectory()
 var error:NSErrorPointer = nil
 let srcUrl = homeDirectory + "/Documents/hangge.txt"
 let toUrl = homeDirectory + "/Documents/copyed.txt"
 fileManager.copyItemAtPath(srcUrl, toPath: toUrl, error: error)

（2）方法2

 // 定位到用户文档目录
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil

 let contentsOfURL = manager.contentsOfDirectoryAtURL(url, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, error: error);
 // 将test.txt文件拷贝到文档目录根目录下的copyed.txt文件
 let srcUrl = url.URLByAppendingPathComponent("test.txt")
 let toUrl = url.URLByAppendingPathComponent("copyed.txt")

 let copyItemSuccess = manager.copyItemAtURL(srcUrl, toURL: toUrl, error: error)
 println("复制结果: \(copyItemSuccess)")

7，移动文件
（1）方法1

 let fileManager = NSFileManager.defaultManager()
 let homeDirectory = NSHomeDirectory()
 var error:NSErrorPointer = nil
 let srcUrl = homeDirectory + "/Documents/hangge.txt"
 let toUrl = homeDirectory + "/Documents/moved"
 fileManager.moveItemAtPath(srcUrl, toPath: toUrl, error: error)

（2）方法2

 // 定位到用户文档目录
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil

 let contentsOfURL = manager.contentsOfDirectoryAtURL(url, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, error: error);
 let srcUrl = url.URLByAppendingPathComponent("test.txt")
 let toUrl = url.URLByAppendingPathComponent("copyed.txt")
 // 移动srcUrl中的文件（test.txt）到toUrl中（copyed.txt）
 let moveItemSuccess = manager.moveItemAtURL(srcUrl, toURL: toUrl, error: error)

8，删除文件
（1）方法1

 let fileManager = NSFileManager.defaultManager()
 let homeDirectory = NSHomeDirectory()
 var error:NSErrorPointer = nil
 let srcUrl = homeDirectory + "/Documents/hangge.txt"
 fileManager.removeItemAtPath(srcUrl, error: error)

（2）方法2

 // 定位到用户文档目录
 let manager = NSFileManager.defaultManager()
 let urlForDocument = manager.URLsForDirectory( NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let url = urlForDocument[] as NSURL
 var error:NSErrorPointer = nil

 let contentsOfURL = manager.contentsOfDirectoryAtURL(url, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsHiddenFiles, error: error);
 let toUrl = url.URLByAppendingPathComponent("copyed.txt")
 // 删除文档根目录下的toUrl路径的文件（copyed.txt文件）
 let removeItemSuccess = manager.removeItemAtURL(toUrl, error: error)
 println("删除结果: \(removeItemSuccess)")

9，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 = NSFileManager.defaultManager()
 var error:NSErrorPointer = nil
 var myDirectory = NSHomeDirectory() + "/Documents/Files"
 var fileArray:[AnyObject]? = fileManager.subpathsAtPath(myDirectory)
 for fn in fileArray!{
     fileManager.removeItemAtPath(myDirectory + "/\(fn)", error: error)
 }

 let fileManager = NSFileManager.defaultManager()
 var error:NSErrorPointer = nil
 var myDirectory = NSHomeDirectory() + "/Documents/Files"
 fileManager.removeItemAtPath(myDirectory, error: error)
 fileManager.createDirectoryAtPath(myDirectory, withIntermediateDirectories: true,
     attributes: nil, error: error)

10，读取文件

 let manager = NSFileManager.defaultManager()
 let urlsForDocDirectory = manager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let docPath:NSURL = urlsForDocDirectory[] as NSURL
 let file = docPath.URLByAppendingPathComponent("test.txt")

 //方法1
 var readHandler = NSFileHandle(forReadingFromURL:file,error:nil)!
 var data = readHandler.readDataToEndOfFile()
 var readString = NSString(data: data, encoding: NSUTF8StringEncoding)
 println("文件内容: \(readString)")
 //方法2
 let data = manager.contentsAtPath(file.path!)
 var readString = NSString(data: data, encoding: NSUTF8StringEncoding)
 println("文件内容: \(readString)")

11，在任意位置写入数据

 let string = "添加一些文字到文件末尾"
 let appendedData = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)
 let writeHandler = NSFileHandle(forWritingToURL:file,error:nil)!
 writeHandler.seekToEndOfFile()
 writeHandler.writeData(appendedData!)

12，文件权限判断

 let manager = NSFileManager.defaultManager()
 let urlsForDocDirectory = manager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let docPath:NSURL = urlsForDocDirectory[] as NSURL
 let file = docPath.URLByAppendingPathComponent("test.txt")

 let readable = manager.isReadableFileAtPath(file.path!)
 println("可读: \(readable)")
 let writeable = manager.isWritableFileAtPath(file.path!)
 println("可写: \(writeable)")
 let executable = manager.isExecutableFileAtPath(file.path!)
 println("可执行: \(executable)")
 let deleteable = manager.isDeletableFileAtPath(file.path!)
 println("可删除: \(deleteable)")

13，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 = NSFileManager.defaultManager()
 let urlsForDocDirectory = manager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let docPath:NSURL = urlsForDocDirectory[] as NSURL
 let file = docPath.URLByAppendingPathComponent("test.txt")

 let attributes = manager.attributesOfItemAtPath(file.path!,error:nil) //结果为AnyObject类型
 println("attributes: \(attributes!)")

14，文件/文件夹比较

 let manager = NSFileManager.defaultManager()
 let urlsForDocDirectory = manager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains:NSSearchPathDomainMask.UserDomainMask)
 let docPath:NSURL = urlsForDocDirectory[] as NSURL
 let contents = manager.contentsOfDirectoryAtPath(docPath.path!,error:nil)!

 //下面比较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
  {
     let path1 = docPath.path! + ] as String)
     let path2 = docPath.path! + ] as String)
     let equal = manager.contentsEqualAtPath(path1,andPath:path2)
     println("比较结果: \(equal)")
 }

码农公寓

文件，文件夹操作

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