NSUrl未存储为NSUserDefault中的absolutestring

Question

我指的是上一篇文章,用于在NSUserDefault中存储iPod库的NSURL.但应用程序关闭后,它不会存储在NSUserDefault中.

我使用其他NSString的在其中做完美NSUserDefaults的存储,但是当我保存NSURL绝对串..它不存储值.

可能是什么原因？？

编辑

以下代码我用来保存NSUserDefault值:

currentItem = [collection.items objectAtIndex:songCount];
songURL = [currentItem valueForProperty:MPMediaItemPropertyAssetURL];
[[NSUserDefaults standardUserDefaults] setObject:[currentItem valueForProperty:MPMediaItemPropertyTitle] forKey:@"songTitle"];
[[NSUserDefaults standardUserDefaults] setObject:[songURL absoluteString] forKey:@"songURL"];
avPlayer = [[AVPlayer alloc] initWithURL:songURL];
NSLog(@"songTitle: %@  songURL : %@",[[NSUserDefaults standardUserDefaults]objectForKey:@"songTitle"], songURL);

当我尝试保存NSURL时出现以下错误:

2011-09-13 18:47:23.258 Tabata Timer[933:707] songURL : ipod-library://item/item.mp3?id=-3715406019015217536
2011-09-13 18:47:23.258 Tabata Timer[933:707] *** -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value 'ipod-library://item/item.mp3?id=-3715406019015217536' of class 'NSURL'.
2011-09-13 18:47:23.260 Tabata Timer[933:707] songTitle : Ghajini
2011-09-13 18:47:24.860 Tabata Timer[933:707] *** -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value 'ipod-library://item/item.mp3?id=-3715406019015217536' of class 'NSURL'.
2011-09-13 18:47:24.963 Tabata Timer[933:707] songURL : ipod-library://item/item.mp3?id=-3715406019015217536
warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.3.5 (8L1)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).

Answer 1

如果要存储NSURL,那么为什么要将其转换为字符串并将其保存为字符串.它会增加你的工作量.

你可以试试这个:

NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];     
[defaults setURL:[NSURL URLWithString:@"http://www.google.com"] forKey:@"urlValue"];
[defaults synchronize];

NSURL *url=[defaults URLForKey:@"urlValue"];
NSLog(@"%@",url);