我遇到了一个奇怪的问题,将 NSDictionary
存储到 NSUserDefaults
,然后检索它会将其转换为 NSCFString
.
这是我保存数据的地方:
- (void)saveProgress
{
// Save our progress to the user defaults.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *progressDict = [NSMutableDictionary dictionary];
if ([defaults objectForKey:@"session_progress"] != nil) {
[progressDict addEntriesFromDictionary:[defaults dictionaryForKey:@"session_progress"]];
}
NSMutableDictionary *targetsDict = [NSMutableDictionary dictionary];
if ([progressDict objectForKey:@"targets"] != nil) {
[targetsDict addEntriesFromDictionary:[progressDict objectForKey:@"targets"]];
}
NSMutableDictionary *trackableDict = [NSMutableDictionary dictionary];
if ([targetsDict objectForKey:@"mda_sao_ext_04"]) {
[trackableDict addEntriesFromDictionary:[targetsDict objectForKey:@"mda_sao_ext_04"]];
}
[trackableDict setObject:[NSNumber numberWithBool:YES]
forKey:@"viewed"];
NSLog(@"SAVE Trackable %@ %@", [trackableDict class], trackableDict);
[targetsDict setObject:trackableDict
forKey:@"mda_sao_ext_04"];
NSLog(@"SAVE Targets %@ %@", [targetsDict class], targetsDict);
[progressDict setObject:targetsDict
forKey:@"targets"];
[defaults setObject:progressDict
forKey:@"session_progress"];
[defaults synchronize];
}
这是我加载数据的地方:
- (NSInteger)loadProgress
{
// Load our progress from the user defaults.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:@"session_progress"] == nil) {
trả về 0;
}
NSDictionary *progressDict = [defaults dictionaryForKey:@"session_progress"];
if ([progressDict objectForKey:@"targets"] == nil) {
trả về 0;
}
NSDictionary *targetsDict = [progressDict objectForKey:@"targets"];
NSLog(@"LOAD Targets %@ %@", [targetsDict class], targetsDict);
NSInteger viewedCount = 0;
for (NSDictionary *trackableDict in targetsDict) {
NSLog(@"LOAD Trackable %@ %@", [trackableDict class], trackableDict);
if ([[trackableDict objectForKey:@"viewed"] boolValue]) {
++viewedCount;
}
}
return viewedCount;
}
应用程序在 loadProgress
中崩溃。这是控制台的输出:
LOAD Targets __NSCFDictionary {
"mda_sao_ext_04" = {
scanned = 1;
viewed = 1;
};
}
LOAD Trackable __NSCFString mda_sao_ext_04
从第一个跟踪可以看出,`mda_sao_ext_04 是一个字典,但由于某种原因,它被转换为一个字符串。
有什么想法或建议吗?谢谢!
NSDictionary 的快速枚举返回键,而不是值。
for (NSDictionary *trackableDict in targetsDict) {
在这里你遍历了所有的键。变化
NSLog(@"LOAD Trackable %@ %@", [trackableDict class], trackableDict);
đến
NSLog(@"LOAD Trackable %@ %@", [trackableDict class], targetsDict[trackableDict]);
Tôi là một lập trình viên xuất sắc, rất giỏi!