NSBundle的使用，注意mainBundle和Custom Bundle的區別

1、[NSBundle mainBundle]，文件夾其實是Group，如左側的樹形文件管理器

Build之后，文件直接就復制到了根目錄下，於是讀取的方法，應該是這樣：

NSString *earth = [[NSBundle mainBundle] pathForResource:@"Brad Cox" ofType:@"png"];

2、使用文件夾的時候，Build結果

依然使用同樣的方法，不需要制定文件夾路徑

//inDirectory參數可有可無

NSString *earth = [[NSBundle mainBundle] pathForResource:@"Matthijs" ofType:@"png" inDirectory:@"Images/MoreImages"]; 
NSString *earth = [[NSBundle mainBundle] pathForResource:@"Matthijs" ofType:@"png"];

 

編譯之后，mainBundle的資源都是放到RootFolder下，所以，可以直接訪問，不要指定內部路徑

 

3、使用其他的Bundle

 

NSString *resourceBundle = [[NSBundle mainBundle] pathForResource:@"Resources" ofType:@"bundle"];
    NSLog(@"resourceBundle: %@", resourceBundle);
    NSString *earth = [[NSBundlebundleWithPath:resourceBundle] pathForResource:@"Matthijs"ofType:@"jpg"inDirectory:@"Images/MoreImages"];

    NSLog(@"path: %@", earth);   

使用Custom bundle，訪問內部的子文件夾，需要指定inDirectory參數，這個mainBundle不同，這是為何？

注意：Since
bundles other than the main bundle can have folders embedded inside them, to access
files inside folders of a bundle other than the main bundle it is best to use the pathFor
Resource:ofType:inDirectory: method of NSBundle to explicitly specify the folder in
which a specific file/resource exists.