一、Sandbox沙盒特点：
1、应用程序之间相互隔离；
2、应用程序只能访问自己本地的内容，不能访问其他app文件目录结构（越狱手机除外）；
3、为应用程序构建一个完整的运行空间；
4、应用程序有自己的缓存和数据备份。
二、沙盒目录结构：
1、Documnets；
2、HellWord.app
3、Library;
4、Tmp;
三、app所在沙盒Sandbox目录：
模拟器：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD
真机：
/var/mobile/Applications/8F08C873-76C7-406F-AEAD-B499137787DD
四、获取App Home目录
获取Home目录：
NSString *homeDirectory = NSHomeDirectory();
结果类似：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD
五、HelloWorld.app 目录
NSString *appPath =[ [NSBundle MainBundle] BundlePath];
结果类似：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD/HelloWorld.app
六、获取Documents目录
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectoey,NSUserDomainMask,YES);
NSString *path = [paths objectAtIndex:0];
结果类似：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD/Documents
七、获取Library 目录
NSArray *path = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask,YES);
NSString *path = [paths objectAtIndex:0];
结果类似：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD/Library
八、获取Caches目录
NSArray *path = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask,YES);
NSString *path = [paths objectAtIndex:0];
结果类似：
九、获取Tmp目录
NSString *tmpDir = NSTemporaryDirectory();
结果类似：
~/Library/Application Support/iPhone Simulator/6.0/Applications/8F08C873-76C7-406F-AEAD-B499137787DD/Tmp
十、获取应用程序程序包中资源文件路径的方法：
例如获取程序包中一个图片资源（apple.png）路径的方法：NSString *imagePath = [[NSBundle mainBundle] pathForResource:@”apple” ofType:@”png”];UIImage *appleImage = [[UIImage alloc] initWithContentsOfFile:imagePath];//1)第一种情况，文件图标是黄色的，文件夹是假的，都会拷贝到HelloWorld.app 中
//而且文件名称不能重名 NSString *imagePath = [[NSBundle mainBundle]pathForResource:@"1" ofType:@".jpg"]; NSLog(@"image is %@",imagePath); NSString *imagePath2 = [[NSBundle mainBundle ]pathForResource:@"2.jpg" ofType:nil]; NSLog(@"image2 is %@",imagePath2); //Users/L-ios/Library/Developer/CoreSimulator/Devices/F5988D84-CB68-4DEC-805E-414D905304BE/data/Containers/Bundle/Application/528B83A0-F896-4759-8B57-D4EE2DCDBBE6/各种目录获取.app/image2/1.jpg //2)第二种情况，文件夹图标是绿色的，这个文件真实存在，内容拷贝到HelloWorld.app中， NSString *image2Path = [[NSBundle mainBundle]pathForResource:@"1" ofType:@"jpg" inDirectory:@"image2"]; NSLog(@"image2path is %@",image2Path); NSString *image2Path2 = [[NSBundle mainBundle]pathForResource:@"2.jpg" ofType:nil inDirectory:@"image2"]; NSLog(@"image2Path2 is %@ ",image2Path2);