iOS中文件操作(NSFileManager)

iOS的沙盒机制，应用只能访问当前应用目录下的文件内容。应用内所产生的如图像、文件、缓存等内容也都必须存储在自己的沙盒内。
默认情况下，每个沙盒含有3个文件夹：Documents, Library 和 tmp。

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其中Library包含Caches、Preferences目录。

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(完整路径为:/Users/xxxx/Library/Developer/CoreSimulator/Devices)

沙盒结构

Application：存放程序源文件，上架前经过数字签名，上架后不可修改
Documents：常用目录，iCloud备份目录，存放数据,这里不能存缓存文件,否则上架
不被通过
Library:
&Caches：存放体积大又不需要备份的数据,比如下载的音乐,视频,SDWebImage缓存等
&Preference：设置目录，iCloud会备份设置信息
tmp：存放临时文件，不会被备份，而且这个文件下的数据有可能随时被清除的可能

1,如何获取沙盒根路径

-(void)directoryHome{

NSString *directoryHome=NSHomeDirectory();

NSLog(@"app_home: %@",directoryHome);

}

2,获取Documents目录

-(NSString *)dirDoc{

//[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, 
NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

NSLog(@"app_home_doc: %@",documentsDirectory);

return documentsDirectory;
}

3,获取Library目录路径：

//获取Library目录
-(void)dirLib{

//[NSHomeDirectory() stringByAppendingPathComponent:@"Library"];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);

NSString *libraryDirectory = [paths objectAtIndex:0];

NSLog(@"app_home_lib: %@",libraryDirectory);

}```

4,获取Cache目录路径：

//获取Cache目录
-(void)dirCache{

NSArray *cacPath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);

NSString *cachePath = [cacPath objectAtIndex:0];

NSLog(@"app_home_lib_cache: %@",cachePath);

}```

5,获取Tmp目录路径：

//获取Tmp目录
-(void)dirTmp{

//[NSHomeDirectory() stringByAppendingPathComponent:@"tmp"];

NSString *tmpDirectory = NSTemporaryDirectory();

NSLog(@"app_home_tmp: %@",tmpDirectory);

}```

6,创建文件夹：

//创建文件夹
-(void *)createDir{

NSString *documentsPath =[self dirDoc];

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

}

创建目录

BOOL res=[fileManager createDirectoryAtPath:testDirectory withIntermediateDirectories:YES attributes:nil error:nil];`

if (res) {

NSLog(@"文件夹创建成功");

}else

NSLog(@"文件夹创建失败");

}```

7,创建文件

//创建文件
-(void *)createFile{

NSString *documentsPath =[self dirDoc];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];

BOOL res=[fileManager createFileAtPath:testPath contents:nil attributes:nil];

if (res) {

NSLog(@"文件创建成功: %@" ,testPath);

}else

NSLog(@"文件创建失败");

}```

8,写数据到文件

//写文件
-(void)writeFile{

NSString *documentsPath =[self dirDoc];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];

NSString *content=@"测试写入内容！";

BOOL res=[content writeToFile:testPath atomically:YES encoding:NSUTF8StringEncoding error:nil];

if (res) {

NSLog(@"文件写入成功");

}else

NSLog(@"文件写入失败");

}```

9,读文件数据：

//读文件
-(void)readFile{

NSString *documentsPath =[self dirDoc];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];

//    NSData *data = [NSData dataWithContentsOfFile:testPath];

//    NSLog(@"文件读取成功: %@",[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);

NSString *content=[NSString stringWithContentsOfFile:testPath encoding:NSUTF8StringEncoding error:nil];

NSLog(@"文件读取成功: %@",content);

}```

10,文件属性：

//文件属性
-(void)fileAttriutes{

NSString *documentsPath =[self dirDoc];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];

NSDictionary *fileAttributes = [fileManager attributesOfItemAtPath:testPath error:nil];

NSArray *keys;

id key, value;

keys = [fileAttributes allKeys];

int count = [keys count];

for (int i = 0; i < count; i++)

{

key = [keys objectAtIndex: i];

value = [fileAttributes objectForKey: key];

NSLog (@"Key: %@ for value: %@", key, value);

}

}```

11,删除文件

//删除文件
-(void)deleteFile{

NSString *documentsPath =[self dirDoc];

NSString *testDirectory = [documentsPath stringByAppendingPathComponent:@"test"];

NSFileManager *fileManager = [NSFileManager defaultManager];

NSString *testPath = [testDirectory stringByAppendingPathComponent:@"test.txt"];

BOOL res=[fileManager removeItemAtPath:testPath error:nil];

if (res) {

NSLog(@"文件删除成功");

}else

NSLog(@"文件删除失败");

NSLog(@"文件是否存在: %@",[fileManager isExecutableFileAtPath:testPath]?@"YES":@"NO");

}