Bundles

Bundle是Cocoa 应用程序中资源的组织方法，它是一个以.bundle为扩展名的文件夹，Cocoa 提供了对它操作的方法。

@interface NSBundle : NSObject {
@private
    NSUInteger        _flags;
    id                _cfBundle;
    NSUInteger        _reserved2;
    Class        _principalClass;
    id                  _tmp1;
    id                  _tmp2;
    void        *_reserved1;
    void        *_reserved0;
}

/* Methods for creating or retrieving bundle instances. */
+ (NSBundle *)mainBundle;
+ (NSBundle *)bundleWithPath:(NSString *)path;
- (id)initWithPath:(NSString *)path;

+ (NSBundle *)bundleWithURL:(NSURL *)url NS_AVAILABLE(10_6, 4_0);
- (id)initWithURL:(NSURL *)url NS_AVAILABLE(10_6, 4_0);

+ (NSBundle *)bundleForClass:(Class)aClass;
+ (NSBundle *)bundleWithIdentifier:(NSString *)identifier;

+ (NSArray *)allBundles;
+ (NSArray *)allFrameworks;

/* Methods for loading and unloading bundles. */
- (BOOL)load;
- (BOOL)isLoaded;
- (BOOL)unload;

- (BOOL)preflightAndReturnError:(NSError **)error NS_AVAILABLE(10_5, 2_0);
- (BOOL)loadAndReturnError:(NSError **)error NS_AVAILABLE(10_5, 2_0);

/* Methods for locating various components of a bundle. */
- (NSURL *)bundleURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)resourceURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)executableURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)URLForAuxiliaryExecutable:(NSString *)executableName NS_AVAILABLE(10_6, 4_0);

- (NSURL *)privateFrameworksURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)sharedFrameworksURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)sharedSupportURL NS_AVAILABLE(10_6, 4_0);
- (NSURL *)builtInPlugInsURL NS_AVAILABLE(10_6, 4_0);

- (NSURL *)appStoreReceiptURL NS_AVAILABLE_MAC(10_7);

- (NSString *)bundlePath;
- (NSString *)resourcePath;
- (NSString *)executablePath;
- (NSString *)pathForAuxiliaryExecutable:(NSString *)executableName;

- (NSString *)privateFrameworksPath;
- (NSString *)sharedFrameworksPath;
- (NSString *)sharedSupportPath;
- (NSString *)builtInPlugInsPath;

/* Methods for locating bundle resources.  Instance methods locate resources in the bundle indicated by the receiver; class methods take an argument pointing to a bundle on disk.  In the class methods, bundleURL is a URL pointing to the location of a bundle on disk, and may not be nil; bundlePath is the path equivalent of bundleURL, an absolute path pointing to the location of a bundle on disk.  By contrast, subpath is a relative path to a subdirectory inside the relevant global or localized resource directory, and should be nil if the resource file in question is not in a subdirectory.  Where appropriate, localizationName is the name of a .lproj directory in the bundle, minus the .lproj extension; passing nil for localizationName retrieves only global resources, whereas using a method without this argument retrieves both global and localized resources (using the standard localization search algorithm).  */

+ (NSURL *)URLForResource:(NSString *)name withExtension:(NSString *)ext subdirectory:(NSString *)subpath inBundleWithURL:(NSURL *)bundleURL NS_AVAILABLE(10_6, 4_0);
+ (NSArray *)URLsForResourcesWithExtension:(NSString *)ext subdirectory:(NSString *)subpath inBundleWithURL:(NSURL *)bundleURL NS_AVAILABLE(10_6, 4_0);

- (NSURL *)URLForResource:(NSString *)name withExtension:(NSString *)ext NS_AVAILABLE(10_6, 4_0);
- (NSURL *)URLForResource:(NSString *)name withExtension:(NSString *)ext subdirectory:(NSString *)subpath NS_AVAILABLE(10_6, 4_0);
- (NSURL *)URLForResource:(NSString *)name withExtension:(NSString *)ext subdirectory:(NSString *)subpath localization:(NSString *)localizationName NS_AVAILABLE(10_6, 4_0);

- (NSArray *)URLsForResourcesWithExtension:(NSString *)ext subdirectory:(NSString *)subpath NS_AVAILABLE(10_6, 4_0);
- (NSArray *)URLsForResourcesWithExtension:(NSString *)ext subdirectory:(NSString *)subpath localization:(NSString *)localizationName NS_AVAILABLE(10_6, 4_0);

+ (NSString *)pathForResource:(NSString *)name ofType:(NSString *)ext inDirectory:(NSString *)bundlePath;
+ (NSArray *)pathsForResourcesOfType:(NSString *)ext inDirectory:(NSString *)bundlePath;

- (NSString *)pathForResource:(NSString *)name ofType:(NSString *)ext;
- (NSString *)pathForResource:(NSString *)name ofType:(NSString *)ext inDirectory:(NSString *)subpath;
- (NSString *)pathForResource:(NSString *)name ofType:(NSString *)ext inDirectory:(NSString *)subpath forLocalization:(NSString *)localizationName;

- (NSArray *)pathsForResourcesOfType:(NSString *)ext inDirectory:(NSString *)subpath;
- (NSArray *)pathsForResourcesOfType:(NSString *)ext inDirectory:(NSString *)subpath forLocalization:(NSString *)localizationName;

/* Method for retrieving localized strings. */
- (NSString *)localizedStringForKey:(NSString *)key value:(NSString *)value table:(NSString *)tableName NS_FORMAT_ARGUMENT(1);

/* Methods for obtaining various information about a bundle. */
- (NSString *)bundleIdentifier;
- (NSDictionary *)infoDictionary;
- (NSDictionary *)localizedInfoDictionary;
- (id)objectForInfoDictionaryKey:(NSString *)key;
- (Class)classNamed:(NSString *)className;
- (Class)principalClass;

/* Methods for dealing with localizations. */
- (NSArray *)localizations;
- (NSArray *)preferredLocalizations;
- (NSString *)developmentLocalization;

+ (NSArray *)preferredLocalizationsFromArray:(NSArray *)localizationsArray;
+ (NSArray *)preferredLocalizationsFromArray:(NSArray *)localizationsArray forPreferences:(NSArray *)preferencesArray;

/* Method for determining executable architectures. */
enum {
    NSBundleExecutableArchitectureI386      = 0x00000007,
    NSBundleExecutableArchitecturePPC       = 0x00000012,
    NSBundleExecutableArchitectureX86_64    = 0x01000007,
    NSBundleExecutableArchitecturePPC64     = 0x01000012
};

- (NSArray *)executableArchitectures NS_AVAILABLE(10_5, 2_0);

@end

main bundle是应用程序的根束，所有的文件都在这个束中。

NSString *path = [NSBundle main bundle] pathForResource: @"default.png"
                                                        ofType: @"png";
if(path !=nil){ };

读取其它的束

NSString *bundlePath = [NSBundle mainbundle] pathForResouce: @"Resources"  ofType: @"bundle"];
if(bundlePath !=nil)
{
    NSBundle *resourcesBundle = [NSBundle bundleWithPath: bundlePath];
    if(resoucesBundle != nil)
    {    }
}