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我正在尝试在我的应用程序上使用“添加到收藏夹”功能。我似乎无法让它正常工作。基本上每次我的手机重启时，所有收藏夹都会从数组和字典中删除。有没有办法保存这些数据，以便在每次应用启动时保存和恢复？非常感谢。

这是一些代码：在 appDidFinishLaunching 中：

//============== Add To Favourites ==============

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Saved.data"];


NSArray *pathsArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryArray = [pathsArray objectAtIndex:0];
NSString *filePathArray = [documentsDirectoryArray stringByAppendingPathComponent:@"savedArray.data"];

delegateFavouritesDictionary = [NSMutableDictionary dictionary];
[delegateFavouritesDictionary writeToFile:filePath atomically:YES];

    delegateFavouritesArray = [[NSMutableArray alloc]init];

在 detailViewController viewDidLoad 中：

self.addToFavouritesArray = [[NSMutableArray alloc] init];
self.addToFavouritesDictionary = [NSMutableDictionary dictionary];
TabBar_NavigationBasedAppDelegate *mainDelegate = (TabBar_NavigationBasedAppDelegate *)[[UIApplication sharedApplication]delegate];
//addToFavouritesArray = [[NSMutableArray alloc] init];
NSMutableArray *tempArray1 = mainDelegate.delegateFavouritesArray;
//NSMutableDictionary *tempDictionary1 = mainDelegate.delegateFavouritesDictionary;
addToFavouritesArray = tempArray1;

//self.addToFavouritesDictionary = tempDictionary1;


NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Saved.data"];
addToFavouritesDictionary = [[NSMutableDictionary alloc] initWithContentsOfFile:filePath];

在 detailViewController 中，在 addToFavourites 函数中：

NSString *ID = [[NSUserDefaults standardUserDefaults]objectForKey:@"ID"];

    if([[addToFavouritesDictionary allKeys] containsObject:ID]) {

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Saved.data"];



        [addToFavouritesDictionary removeObjectForKey:ID];
        [addToFavouritesArray removeObject:Name];
        [favouritesButton setTitle:@"+ Favourites" forState:(UIControlState)UIControlStateNormal];
        [addToFavouritesDictionary writeToFile:filePath atomically: YES];
        NSLog(@"New Dictionary: %@", addToFavouritesDictionary);

    } else {

        [addToFavouritesArray addObject:Name];
        NSString *ID = [[NSUserDefaults standardUserDefaults]objectForKey:@"ID"];
        [addToFavouritesDictionary setObject:Name forKey:ID];
        [favouritesButton setTitle:@"- Favourites" forState:(UIControlState)UIControlStateNormal];

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Saved.data"];

        [addToFavouritesDictionary writeToFile:filePath atomically: YES];
        NSLog(@"Mutable Dictionary: %@", addToFavouritesDictionary);
        //[addToFavouritesDictionary release];

    }

在 FavouritesViewController 中，在 viewDidLoad 中：

TabBar_NavigationBasedAppDelegate *mainDelegate = (TabBar_NavigationBasedAppDelegate *)[[UIApplication sharedApplication]delegate];


favouritesArray = [[NSMutableArray alloc] init];

NSMutableArray *tempArray1 = mainDelegate.delegateFavouritesArray;
favouritesArray = tempArray1;

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Saved.data"];


favouritesDictionary = [[NSMutableDictionary alloc] initWithContentsOfFile:filePath];

非常感谢您的帮助

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1 回答 1

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在您的 applicationDidFinishLaunching: 方法中（因此每次启动您的应用程序时），您首先创建一个空的 NSMutableDictionary，然后将其写入 Saved.data，可能会覆盖任何可能存在的内容。

于 2011-05-15T23:24:24.577 回答