Question

我正在尝试使用NSCoding从我的应用中保存一些值。我可以保存值但无法检索它。

这是我宣布协议的地方：

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

这是我遵守协议的地方：

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

在这里：

-(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; }

这里是我调用归档和取消归档的方法：

    [self saveDataToDisk];
    [self loadDataFromDisk];

以下是这些方法的主体，它是NSLog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;}

这里是unarchiver代码及其NSLog内容：

- (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)

我错过了什么，我无法取消归档内容？我只关注我的编码器/解码器方法中最简单的值来测试它，但我甚至无法使字符串值起作用。

由于

Answer 1

保存和加载提醒的路径是错误的。也许替换为这个

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

NSCoding NSKeyedUnarchiver unarchiveObjectWithFile：返回null

1 个答案: