NSSearchPathDirectory的一些用途枚舉

Question

如何使用枚舉NSMoviesDirectory或NSMusicDirectory。文檔說，我們可以從ios 4開始使用它們，但在我的應用程序中我找不到如何在那裏複製文件的方法？ 爲什麼蘋果如果我們不能使用它們就添加了這些枚舉？

Answer 1

只寫樣本，音樂目錄（或別的東西）默認情況下不存在，你應該編碼創建它。 樣本：

- (void)testDir 
{ 
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSMusicDirectory, NSUserDomainMask, YES); 
    NSString *musicDirectory = [paths objectAtIndex:0]; 
    NSFileManager *defaultFileManager = [NSFileManager defaultManager]; 
    if (![defaultFileManager fileExistsAtPath:musicDirectory]) { 
     [defaultFileManager createDirectoryAtPath:musicDirectory withIntermediateDirectories:NO attributes:nil error:NULL]; 
    } 
    NSString *testDataFilePath = [musicDirectory stringByAppendingPathComponent:@"test.mp3"]; 
    unsigned int bufferLength = 1024; 
    void *buffer = malloc(1024 * sizeof(char)); 
    NSData *testData = [[NSData alloc] initWithBytes:buffer length:bufferLength]; 
    free(buffer); buffer = NULL; 
    if (![testData writeToFile:testDataFilePath atomically:NO]) { 
     NSLog(@"fail to save data"); 
    } 
    [testData release]; testData = nil; 
} 

Answer 2

默認情況下，「電影」，「音樂」和「圖片」會不會在目錄中。 您必須創建路徑並放置數據文件。

如：NSMoviesDirectory

NSArray * paths = NSSearchPathForDirectoriesInDomains (NSMoviesDirectory,NSUserDomainMask, YES); 
NSString * documentsDirectory = [paths objectAtIndex:0]; 
NSError * error; 
if (![[NSFileManager defaultManager] fileExistsAtPath: documentsDirectory]) 
{ 
    [[NSFileManager defaultManager] createDirectoryAtPath:documentsDirectory withIntermediateDirectories:NO attributes:nil error:&error]; 
    NSString * resourceDBFolderPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"sleep.mp4"]; 
    [[NSFileManager defaultManager] copyItemAtPath:resourceDBFolderPath toPath:[documentsDirectory stringByAppendingPathComponent:@"sleep.mp4"] error:&error]; 

} 
else 
{ 
    NSString * resourceDBFolderPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"sleep.mp4"]; 
    [[NSFileManager defaultManager] copyItemAtPath:resourceDBFolderPath toPath:[documentsDirectory stringByAppendingPathComponent:@"sleep.mp4"] error:&error]; 

}