文件管理类NSFileManager类：对文件进行创建、复制、重命名、删除等，一般不对文件内容进行操作。
NSData类和NSMutableData类：相当于数据缓冲区
NSFileManager是一个单例类,可以通过defalutManager类方法创建
+ (NSFileManager *)defaultManager;//通过这个方法创建的对象始终是同一个
一些文件操作的概念：
-当前目录：.
-上级目录：..
-根目录：/
-home目录：~
-绝对路径：从根目录开始的路经
-相对路径：从当前目录开始的路径
| 方法 | 描述 |
|---|---|
| -(NSData ) contentsAtPath: *path | 从一个文件读取数据 |
| -(BOOL) createFileAtPath: path contents: (NSData ) *data attributes: attr | 向一个文件写入数据 |
| -(`BOOL) removeItemAtPath: path error: err | 删除一个文件 |
| -(BOOL) moveItemAtPath: from toPath: to error: err | 重命名或移动一个文件(to不能是已存在的) |
| -(BOOL) copyItemAtPath: from toPath: to error: err | 复制一个文件(to不能是已存在的) |
| -(BOOL) contentsEqualAtPath: path1 andPath: path2 | 比较这两个文件的内容 |
| -(BOOL) fileExistsAtPath: path | 测试文件是否存在 |
| -(BOOL) isReadableFileAtPath: path | 测试文件是否存在且是可读文件 |
| -(BOOL) isWritableFileAtPath: path | 测试文件是否存在且是可写文件 |
| -(NSDictionary ) attributesOfItemAtPath: *path error: err | 获取文件的属性 |
| -(BOOL) setAttributesOfItemAtPath: attr error: err | 更改文件的属性 |
| —————-目录—————- | —————目录—————- |
| -(NSString *) currentDirectoryPath | 获取当前目录 |
| -(BOOL) changeCurrentDirectoryPath: path | 更改当前目录 |
| -(BOOL) copyItemAtPath: from toPath: to error: err | 复制目录结构(to不能是已存在的) |
| -(BOOL) createDirectoryAtPath: path withIntermediateDirectories: (BOOL) flag attributes: attr | 创建一个新目录 |
| -(NSArray ) contentsOfDirectoryAtPath: *path error: err | 列出目录内容 |
| -(NSDirectoryEnumerator ) enumeratorAtPath: *path | 枚举目录的内容 |
| -(BOOL) removeItemAtPath: path error: err | 删除空目录 |
| -(BOOL) moveItemAtPath: from toPath: to error: err | 重命名或移动一个目录(to不能是已存在的) |
1、 创建NSFileManager对象,其实都是同一个对象
1 NSFileManager *fm = [NSFileManager defaultManager];
2 NSFileManager *fm2 = [NSFileManager defaultManager];
3
4 NSLog(@"%@,%@",fm,fm2);
2015-08-24 20:28:23.744 01-NSFlleManager[861:32223] <NSFileManager: 0x100306940>,<NSFileManager: 0x100306940>
2、获取当前路径
1 NSString *currentPath = [fm currentDirectoryPath];
2 NSLog(@"当前目录:%@0",currentPath);
2015-08-24 20:29:15.624 01-NSFlleManager[869:32586] 当前目录:/Users/mac/Library/Developer/Xcode/DerivedData/01-NSFlleManager-bjtgjiggpfdimgemqrewbfyjlwwu/Build/Products/Debug0 Program ended with exit code: 0
3、改变当前路径
1 [fm changeCurrentDirectoryPath:@".."];
2 currentPath = [fm currentDirectoryPath];
3 NSLog(@"当前目录:%@0",currentPath);
2015-08-24 20:30:54.837 01-NSFlleManager[878:33188] 当前目录:/Users/mac/Library/Developer/Xcode/DerivedData/01-NSFlleManager-bjtgjiggpfdimgemqrewbfyjlwwu/Build/Products0 Program ended with exit code: 0
4.创建目录
1 NSError *error;
2 [fm createDirectoryAtPath:@"temp" withIntermediateDirectories:YES attributes:nil error:&error];
3 if(error)
4 {
5 NSLog(@"创建目录错误：%@",error);
6 }
7 else
8 {
9 NSLog(@"创建成功");
10 }
11
12 [fm changeCurrentDirectoryPath:@"temp"];
13 currentPath = [fm currentDirectoryPath];
14 NSLog(@"当前目录:%@0",currentPath);
2015-08-24 20:32:48.230 01-NSFlleManager[886:33837] 创建成功 2015-08-24 20:32:48.230 01-NSFlleManager[886:33837] 当前目录:/Users/mac/Library/Developer/Xcode/DerivedData/01-NSFlleManager-bjtgjiggpfdimgemqrewbfyjlwwu/Build/Products/temp0 Program ended with exit code: 0
5.复制文件(目录)
1 [fm copyItemAtPath:@"../Debug/01-NSFlleManager" toPath:@"./02-NSFlleManager" error:&error];
2 if(error)
3 {
4 NSLog(@"复制文件失败：%@",error);
5 }
6 else
7 {
8 NSLog(@"复制文件成功");
9 }
6.移动文件(目录)，在同一个目录下改名操作
1 [fm moveItemAtPath:@"02-NSFlleManager" toPath:@"03-NSFlleManager" error:&error];
2 if(error)
3 {
4 NSLog(@"文件移动失败：%@",error);
5 }
6 else
7 {
8 NSLog(@"文件移动成功");
9 }
7.删除文件(目录)
1 error = nil;
2 [fm removeItemAtPath:@"../01-NSFlleManager" error:&error];
3 if(error)
4 {
5 NSLog(@"文件删除失败：%@",error);
6 }
7 else
8 {
9 NSLog(@"文件删除成功");
10 }
8.枚举目录内容
8.1 递归输出所有目录的内容
1 NSDirectoryEnumerator *dirEnumerator = [fm enumeratorAtPath:@"/Users/mac/IOS/OC"];
2 NSString *path;
3 while(path = [dirEnumerator nextObject])
4 {
5 NSLog(@"%@",path);
6 }
8.2 .只输出当前目录的内容
1 NSArray *files = [fm contentsOfDirectoryAtPath:@"/Users/mac/IOS/OC" error:&error];
2 NSLog(@"%@",files);
9.列出目录(文件)的属性
1 NSDictionary *attr = [fm attributesOfItemAtPath:@"/Users/mac/IOS/OC" error:&error];
2 NSLog(@"%@",attr);
2015-08-24 20:40:56.755 01-NSFlleManager[912:36354] { NSFileCreationDate = "2015-08-10 01:39:40 +0000"; NSFileExtensionHidden = 0; NSFileGroupOwnerAccountID = 20; NSFileGroupOwnerAccountName = staff; NSFileModificationDate = "2015-08-24 01:22:42 +0000"; NSFileOwnerAccountID = 501; NSFileOwnerAccountName = mac; NSFilePosixPermissions = 493; NSFileReferenceCount = 13; NSFileSize = 442; NSFileSystemFileNumber = 1685728; NSFileSystemNumber = 16777218; NSFileType = NSFileTypeDirectory; } Program ended with exit code: 0
10.创建文件
1 NSString *str = @"this is a test";
2 NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
3 if([fm createFileAtPath:@"1.txt" contents:data attributes:nil])
4 {
5 NSLog(@"创建文件成功");
6 }
7 else
8 {
9 NSLog(@"创建文件失败");
10 }
11.判断文件是否存在
1 if([fm fileExistsAtPath:@"1.txt" isDirectory:NULL])
2 {
3 NSLog(@"文件存在");
4 }
5 else
6 {
7 NSLog(@"文件不存在");
8 }
12.读取文件内容
1 NSData *data2 = [fm contentsAtPath:@"1.txt"];
2 NSLog(@"%ld",[data2 length]);
3 NSString *str2 = [[NSString alloc]initWithData:data2 encoding:NSUTF8StringEncoding];
4 NSLog(@"%@",str2);
2015-08-24 20:44:33.660 01-NSFlleManager[920:37495] this is a test Program ended with exit code: 0
