IOS - 按順序加載本地文件

Question

我有一個應用程序的文檔文件夾中的圖像列表，我想按創建日期的順序加載圖像。 我該怎麼做？

Answer 1

此代碼將枚舉所有文件在你的文件目錄下創建它們的順序：

見註釋中的代碼，瞭解正在發生的事情。

NSFileManager *fm = [NSFileManager defaultManager]; 
NSString *doc = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 
NSError *err; 
// Get all files with their creation date 
NSArray *files = [fm contentsOfDirectoryAtURL:[[NSURL alloc] initFileURLWithPath:doc isDirectory:YES] 
    includingPropertiesForKeys:[NSArray arrayWithObject:NSURLCreationDateKey] 
    options:0 
    error:&err]; 
// Using file's URL as the key, store creation date as the value 
NSMutableDictionary *urlWithDate = [NSMutableDictionary dictionaryWithCapacity:files.count]; 
for (NSURL *f in files) { 
    NSDate *creationDate; 
    if ([f getResourceValue:&creationDate forKey:NSURLCreationDateKey error:&err]) { 
     [urlWithDate setObject:creationDate forKey:f]; 
    } 
} 
// Sort the dictionary on the value, which is the creation key 
for (NSURL *f in [urlWithDate keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2) { 
    return [obj1 compare:obj2]; 
}]) { 
    // Check if the file is an image. Load if it is an image, otherwise skip. 
    NSLog(@"%@", f); 
} 

Answer 2

我會看看：Getting a list of files in a directory with a glob

具體的的NSF​​ileManager。您可以查看文件的屬性。從那裏你很可能使用NSPredicate進行排序。