NSCoding NSKeyedUnarchiver unarchiveObjectWithFile：返回null

Question

我想从我的应用程序使用NSCoding保存一些值。我可以保存该值，但无法检索它。

这里就是我声明的协议：

-(void)encodeWithCoder:(NSCoder *)enCoder 
{ 
[enCoder encodeObject:self.eventRepeatDurationDate forKey:kEventRepeatDuration]; 
[enCoder encodeObject:self.eventIDsMutableArray  forKey:kEventIDsMutableArray]; 
[enCoder encodeObject:self.eventRepeatDurationString forKey:@"mytest"];} 

这里：

@interface AddReminderEventViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource, NSCoding> 

这里是我在遵守该协议的其中

-(id)initWithCoder:(NSCoder *)decoder { 

if (self = [super init]){ 

    self.eventRepeatDurationDate = [[decoder decodeObjectForKey:kEventRepeatDuration] retain]; 
    self.eventIDsMutableArray = [[decoder decodeObjectForKey:kEventIDsMutableArray] retain]; 
    self.eventRepeatDurationString = [[decoder decodeObjectForKey:@"mytest"] retain];} return self; } 

这里的地方我请拨打方法进行归档和解除归档：

[self saveDataToDisk]; 
    [self loadDataFromDisk]; 

，以下是这些方法的机构，它的NSLog的内容：

- (void)saveDataToDisk { 
NSString *reminderEventIDsPathString = @"~/Library/Application Support/ReminderIDs.archive";  
//reminderEventIDsPathString = @"~/Library/Application Support/ReminderIDs.archive"; 
reminderEventIDsPathString = [reminderEventIDsPathString stringByExpandingTildeInPath]; 
NSLog(@"WATCH1: reminderEventIDsPathString is %@", reminderEventIDsPathString); 

NSMutableDictionary *rootObject; 
rootObject = [NSMutableDictionary dictionary]; 

[rootObject setValue:eventRepeatDurationString forKey:@"mytest"]; 
NSLog(@"1rootObject IS %@", rootObject); 

[NSKeyedArchiver archiveRootObject:rootObject toFile:reminderEventIDsPathString];} 

reminderEventIDsPathString is /Users/tester/Library/Application Support/iPhone Simulator/5.0/Applications/E26D57DE-C4E1-4318-AEDD-7207F41010A9/Library/Application Support/ReminderIDs.archive 
2012-01-16 15:47:48.578 [29658:15503] 1rootObject IS {mytest = 7;} 

，并在这里与它的NSLog内容一起的取档代码：

- (void)loadDataFromDisk { 
NSString *testValue = [[NSString alloc] init]; 
NSString *reminderEventIDsPathString = @"~/Library/Application Support/ReminderIDs.archive";  
reminderEventIDsPathString = [reminderEventIDsPathString stringByExpandingTildeInPath]; 
NSLog(@"WATCH2: reminderEventIDsPathString is %@", reminderEventIDsPathString); 

NSMutableDictionary *rootObject; 
rootObject = [[NSKeyedUnarchiver unarchiveObjectWithFile:reminderEventIDsPathString] retain]; 

NSLog(@"2rootObject IS %@", rootObject); 

NSLog(@"WATCH3 - %@", [rootObject objectForKey:@"mytest" ]); 

if ([rootObject valueForKey:@"mytest"]) { 
    testValue = [rootObject valueForKey:@"mytest"]; 
    NSLog(@"WATCH: testValue is %@", testValue); } } 

2012-01-16 15:48:14.965 [29658:15503] WATCH2: reminderEventIDsPathString is /Users/tester/Library/Application Support/iPhone Simulator/5.0/Applications/E26D57DE-C4E1-4318-AEDD-7207F41010A9/Library/Application Support/ReminderIDs.archive 

2012-01-16 15:48:17.879 [29658:15503] 2rootObject IS (null) 

我在想什么，我无法解压内容？我只关注我的编码器/解码器方法中最简单的值来测试它，但我甚至无法获得字符串值的工作。

谢谢

Answer 1

您保存和加载您的提醒的路径是错误的。也许替换为此

NSString *reminderEventIDsPathString = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"ReminderIDs.archive"];