将视频保存到NSUserDefault

Question

我想将视频文件保存在NSUserDefaults中。我知道有一种方法可以通过UserDefault中的setURL保存。如何在数组中添加URL？

Answer 1

Add URLs in an array, and save the array in NSUserDefaults

NSArray *urlArray = @[url1, url2, url3];
    [[NSUserDefaults standardUserDefaults] setObject:urlArray forKey:@"UrlArrayKey"];
    [[NSUserDefaults standardUserDefaults] synchronize];

Answer 2

//store urls in NSUserDefaults
NSArray *arrayURLsToStore = [NSArray arrayWithObjects:@"link1", "link2", nil];

[[NSUserDefaults standardUserDefaults] setObject:arrayURLsToStore forKey:@"URLs"];
[[NSUserDefaults standardUserDefaults] synchronize];

//get urls from NSUserDefaults
NSArray *arrURLsRetrived = [[NSUserDefaults standardUserDefaults] objectForKey:@"URLs"];
NSString *urlString = [NSString stringWithFormat:[arrURLsRetrived objectAtIndex:0]];
NSURL *youURL = [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

//now you can use URL1    

Answer 3

The user defaults are a property list. According to the specifications only a few types build property lists.

• NSArray
• NSDictionary
• NSString
• NSNumber
• NSData
• NSDate

Collections (array dictionary) are property lists, if and only if all of their members are property lists.

As you can see from the link, NSURL is no property list. But you can convert an instance of NSURL into a instance of NSString (URL string) at write time …:

NSString *URLString = [URL absoluteString];

… and store this into the array (which stays being a property list, because instances of NSString are property lists).

At read time you can take out the string from the array and convert it back into an instance of NSURL :

NSURL* URL = [NSURL UrlWithString:URLString];

Another way is to convert the instance of NSURL into an instance of NSData and back. This is possible, because NSURL supports NS ( Secure ) Coding .