我正在尝试使用NSUserDefaults存储几个数组。当应用程序终止或启动时，我正在尝试在appDelegate中执行所有操作。但是，我很难让它工作....我能够从应用程序中的任何其他类访问我的数组（项目，任务和团队成员），包括能够向他们添加和删除数据。所以我知道他们正在工作，但我无法保存数据并再次获取。虽然我有一些客观的经验，但我从未试图保存任何应用数据。有人有什么建议吗？这是我AppDelegate的代码
#import "AppDelegate.h"
@implementation AppDelegate
@synthesize window = _window;
@synthesize tasks;
@synthesize teamMembers;
@synthesize projects;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
tasks = [[NSMutableArray alloc]init];
tasks = [prefs objectForKey:@"tasks"];
NSLog(@"There are this many tasks in TASKS after the app loads %@", [tasks count]);
teamMembers = [prefs objectForKey:@"teamMembers"];
projects = [prefs objectForKey:@"projects"];
// Override point for customization after application launch.
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
/*
Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
*/
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSString *theTasks = [[NSString alloc]initWithString:@"tasks"];
NSString *theTeamMembers = [[NSString alloc]initWithString:@"teamMembers"];
NSString *theProjects = [[NSString alloc]initWithString:@"projects"];
[prefs setObject:tasks forKey:theTasks];
[prefs setValue:teamMembers forKey:theTeamMembers];
[prefs setValue:projects forKey:theProjects];
[prefs synchronize];
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
/*
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
*/
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSString *theTasks = [[NSString alloc]initWithString:@"tasks"];
NSString *theTeamMembers = [[NSString alloc]initWithString:@"teamMembers"];
NSString *theProjects = [[NSString alloc]initWithString:@"projects"];
[prefs setObject:tasks forKey:theTasks];
[prefs setValue:teamMembers forKey:theTeamMembers];
[prefs setValue:projects forKey:theProjects];
[prefs synchronize];
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
/*
Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
*/
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
tasks = [prefs objectForKey:@"tasks"];
teamMembers = [prefs objectForKey:@"teamMembers"];
projects = [prefs objectForKey:@"projects"];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
/*
Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
*/
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
tasks = [prefs objectForKey:@"tasks"];
teamMembers = [prefs objectForKey:@"teamMembers"];
projects = [prefs objectForKey:@"projects"];
}
- (void)applicationWillTerminate:(UIApplication *)application
{
/*
Called when the application is about to terminate.
Save data if appropriate.
See also applicationDidEnterBackground:.
*/
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSString *theTasks = [[NSString alloc]initWithString:@"tasks"];
NSString *theTeamMembers = [[NSString alloc]initWithString:@"teamMembers"];
NSString *theProjects = [[NSString alloc]initWithString:@"projects"];
[prefs setObject:tasks forKey:theTasks];
[prefs setValue:teamMembers forKey:theTeamMembers];
[prefs setValue:projects forKey:theProjects];
[prefs synchronize];
}
@end