我对此很陌生，所以请多多包涵。
我使用 iOS 编程构建了一个应用程序:The Big Nerd Ranch Guide 第 4 版，名为 Homepwner，它在应用程序进入后台时利用归档来存储信息，并在应用程序再次启动时加载信息，它运行得非常好。我决定为我自己的名为 SBL 的应用程序实现相同的策略，但是当应用程序退出后加载时，数据似乎已加载但显示不正确。
该应用程序在表格中显示一组“CCIEvent”，它们看起来像示例:
7:00 AM:又湿又脏的尿布
上午 8:48:美联储 - 两者 - 20 分钟
上午 9:48:小睡 - 1 小时 0 分钟
但是当我退出应用程序并再次启动它时，列表会像这样弹出(我必须将其识别为代码才能发布这篇文章，但下面的信息会在我的表格屏幕上显示):
<CCIEvent: 0x154e44e20>
<CCIEvent: 0x154e2c7b0>
<CCIEvent: 0x154e77b90>
我真的不知道去哪里找，但这里是所有与保存/加载相关的代码(我认为):
在 CCIEvent.m 中
- (void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:self.startTime forKey:@"startTime"];
[aCoder encodeObject:self.bedTime forKey:@"bedTime"];
[aCoder encodeObject:self.wakeTime forKey:@"wakeTime"];
[aCoder encodeBool:self.isNap forKey:@"isNap"];
[aCoder encodeInt:self.feedDuration forKey:@"feedDuration"];
[aCoder encodeInt:self.sourceIndex forKey:@"sourceIndex"];
[aCoder encodeInt:self.diaperIndex forKey:@"diaperIndex"];
[aCoder encodeObject:self.note forKey:@"note"];
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
self = [super init];
if (self) {
_startTime = [aDecoder decodeObjectForKey:@"startTime"];
_bedTime = [aDecoder decodeObjectForKey:@"bedTime"];
_wakeTime = [aDecoder decodeObjectForKey:@"wakeTime"];
_isNap = [aDecoder decodeBoolForKey:@"isNap"];
_feedDuration = [aDecoder decodeIntForKey:@"feedDuration"];
_sourceIndex = [aDecoder decodeIntForKey:@"sourceIndex"];
_diaperIndex = [aDecoder decodeIntForKey:@"diaperIndex"];
_note = [aDecoder decodeObjectForKey:@"note"];
}
return self;
}
在 CCIEventStore.m 中
- (instancetype)initPrivate
{
self = [super init];
if (self) {
NSString *path = [self eventArchivePath];
_privateEvents = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
// If the array hadn't been saved previously, create an empty one
if (!_privateEvents) {
_privateEvents = [[NSMutableArray alloc] init];
NSLog(@"Did NOT load events");
} else {
NSLog(@"Loaded events");
}
}
return self;
}
- (CCIEvent *)createEventWithEventType:(NSString *)eventType
startTime:(NSDate *)startTime
bedTime:(NSDate *)bedTime
wakeTime:(NSDate *)wakeTime
isNap:(BOOL)isNap
feedDuration:(int)feedDuration
sourceIndex:(int)sourceIndex
diaperIndex:(int)diaperIndex
note:(NSString *)note
{
CCIEvent *event = [[CCIEvent alloc] initWithEventType:eventType
startTime:startTime
bedTime:bedTime
wakeTime:wakeTime
isNap:isNap
feedDuration:feedDuration
sourceIndex:sourceIndex
diaperIndex:diaperIndex
note:note];
[self.privateEvents addObject:event];
return event;
}
- (NSString *)eventArchivePath
{
NSArray *documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [documentDirectories firstObject];
return [documentDirectory stringByAppendingPathComponent:@"events.archive"];
}
- (BOOL)saveChanges
{
NSString *path = [self eventArchivePath];
return [NSKeyedArchiver archiveRootObject:self.privateEvents
toFile:path];
}
在 AppDelegate.m 中
- (void)applicationDidEnterBackground:(UIApplication *)application {
BOOL success = [[CCIEventStore sharedStore] saveChanges];
if (success) {
NSLog(@"Saved all of the CCIEvents");
} else {
NSLog(@"Could not save any of the CCIEvents");
}
}
这是我称为 CCILogViewController.m 的表所在的 View Controller 中的一些代码:
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setTimeStyle:NSDateFormatterNoStyle];
[dateFormatter setDateStyle:NSDateFormatterShortStyle];
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UITableViewCell"
forIndexPath:indexPath];
CCIEvent *event = self.sortedAndFilteredArray[indexPath.row];
if ([event.eventType isEqualToString:@"sleepEvent"] && event.wakeTime) {
NSDateComponents *dateComponentsToday = [[NSCalendar currentCalendar] components:NSCalendarUnitYear fromDate:[NSDate date]];
NSInteger yearToday = [dateComponentsToday year];
NSInteger dayOfYearToday = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:[NSDate date]];
NSDateComponents *dateComponentsEvent = [[NSCalendar currentCalendar] components:NSCalendarUnitYear
fromDate:event.startTime];
NSInteger yearEvent = [dateComponentsEvent year];
NSInteger dayOfYearEvent = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:event.startTime];
NSInteger dayOfYearWakeEvent;
dayOfYearWakeEvent = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:event.wakeTime];
if (event.wakeTime && yearEvent == yearToday && dayOfYearEvent == dayOfYearToday - 1 && dayOfYearWakeEvent == dayOfYearToday) {
cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [dateFormatter stringFromDate:event.startTime], [self.sortedAndFilteredArray[indexPath.row] description]];
} else if (event.wakeTime && yearEvent == yearToday - 1 && dayOfYearEvent == dayOfYearToday - 1 && dayOfYearEvent == 1 && dayOfYearWakeEvent == dayOfYearToday) {
cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [dateFormatter stringFromDate:event.startTime], [self.sortedAndFilteredArray[indexPath.row] description]];
} else {
cell.textLabel.text = [self.sortedAndFilteredArray[indexPath.row] description];
}
} else if (self.dateOptionIndex == 2 || self.dateOptionIndex == 3) {
cell.textLabel.text = [NSString stringWithFormat:@"%@ %@", [dateFormatter stringFromDate:event.startTime], [self.sortedAndFilteredArray[indexPath.row] description]];
} else {
cell.textLabel.text = [self.sortedAndFilteredArray[indexPath.row] description];
}
if (event.note) {
cell.accessoryType = UITableViewCellAccessoryDetailButton;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
下面是我如何获得 sortedAndFilteredArray，它在几个不同的地方被调用，包括 viewWillAppear:
- (void)sortAndFilterArray
{
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"startTime" ascending:self.arrayIsAscending];
NSArray *sortedArray = [[[CCIEventStore sharedStore] allEvents] sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];
NSMutableArray *sortedAndFilteredArray = [[NSMutableArray alloc] init];
NSMutableArray *finalArray = [[NSMutableArray alloc] init];
for (CCIEvent *event in sortedArray) {
switch (self.eventOptionIndex) {
case 1:
if ([event.eventType isEqualToString:@"sleepEvent"]) {
[sortedAndFilteredArray addObject:event];
}
break;
case 2:
if ([event.eventType isEqualToString:@"feedEvent"]) {
[sortedAndFilteredArray addObject:event];
}
break;
case 3:
if ([event.eventType isEqualToString:@"diaperEvent"]) {
[sortedAndFilteredArray addObject:event];
}
break;
default:
[sortedAndFilteredArray addObject:event];
break;
}
}
NSDateComponents *dateComponentsToday = [[NSCalendar currentCalendar] components:NSCalendarUnitYear fromDate:[NSDate date]];
NSInteger yearToday = [dateComponentsToday year];
NSInteger dayOfYearToday = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:[NSDate date]];
for (CCIEvent *event in sortedAndFilteredArray) {
NSDateComponents *dateComponentsEvent = [[NSCalendar currentCalendar] components:NSCalendarUnitYear
fromDate:event.startTime];
NSInteger yearEvent = [dateComponentsEvent year];
NSInteger dayOfYearEvent = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:event.startTime];
NSInteger dayOfYearWakeEvent;
switch (self.dateOptionIndex) {
case 0:
dayOfYearWakeEvent = [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay
inUnit:NSCalendarUnitYear
forDate:event.wakeTime];
// Filter here for dateIndex 0 (Today)
if ([event.eventType isEqualToString:@"sleepEvent"] && event.wakeTime && yearEvent == yearToday && dayOfYearEvent == dayOfYearToday - 1 && dayOfYearWakeEvent == dayOfYearToday) {
[finalArray addObject:event];
} else if ([event.eventType isEqualToString:@"sleepEvent"] && event.wakeTime && yearEvent == yearToday - 1 && dayOfYearEvent == dayOfYearToday - 1 && dayOfYearEvent == 1 && dayOfYearWakeEvent == dayOfYearToday) {
[finalArray addObject:event];
} else if (yearEvent == yearToday && dayOfYearEvent == dayOfYearToday) {
[finalArray addObject:event];
}
break;
case 1:
// Filter here for dateIndex 1 (Yesterday)
if (yearEvent == yearToday && dayOfYearEvent == dayOfYearToday - 1) {
[finalArray addObject:event];
} else if (yearEvent == yearToday - 1 && dayOfYearEvent == dayOfYearToday - 1 && dayOfYearEvent == 1) {
[finalArray addObject:event];
}
break;
case 2:
// Filter here for dateIndex 2 (Past Week)
if (yearEvent == yearToday && dayOfYearEvent >= dayOfYearEvent - 6) {
[finalArray addObject:event];
} else if (yearEvent == yearToday - 1 && dayOfYearEvent >= dayOfYearToday - 6 && dayOfYearEvent < 7) {
[finalArray addObject:event];
}
break;
default:
// No filter here for dateIndex 3 (All Time)
[finalArray addObject:event];
break;
}
}
self.sortedAndFilteredArray = [finalArray copy];
}
这是在获取 CCIEvent 的描述时调用的内容:
- (NSString *)description
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
[dateFormatter setDateStyle:NSDateFormatterNoStyle];
if ([self.eventType isEqualToString:@"sleepEvent"]) {
NSString *bedTimeString = [dateFormatter stringFromDate:self.bedTime];
NSString *wakeTimeString = [dateFormatter stringFromDate:self.wakeTime];
long min = self.sleepDuration/60;
long hrs = self.sleepDuration/60/60;
long rMinutes = min - hrs * 60;
if (!self.wakeTime && self.bedTime) {
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Went Down for Nap", bedTimeString];
} else {
return [[NSString alloc] initWithFormat:@"%@: Went Down", bedTimeString];
}
} else if (self.wakeTime && !self.bedTime) {
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Woke from Nap", wakeTimeString];
} else {
return [[NSString alloc] initWithFormat:@"%@: Woke", wakeTimeString];
}
} else if (self.sleepDuration <= 60) {
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Napped - 1 min", bedTimeString];
} else {
return [[NSString alloc] initWithFormat:@"%@: Slept - 1 min", bedTimeString];
}
} else if (self.sleepDuration > 60 && self.sleepDuration < 60 * 60){
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Napped - %ld min", bedTimeString, min];
} else {
return [[NSString alloc] initWithFormat:@"%@: Slept - %ld min", bedTimeString, min];
}
} else if (hrs == 1) {
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Napped - 1 hr %ld min", bedTimeString, rMinutes];
} else {
return [[NSString alloc] initWithFormat:@"%@: Slept - 1 hr %ld min", bedTimeString, rMinutes];
}
} else {
if (self.isNap) {
return [[NSString alloc] initWithFormat:@"%@: Napped - %ld hrs %ld min", bedTimeString, hrs, rMinutes];
} else {
return [[NSString alloc] initWithFormat:@"%@: Slept - %ld hrs %ld min", bedTimeString, hrs, rMinutes];
}
}
} else if ([self.eventType isEqualToString:@"feedEvent"]) {
NSString *startTimeString = [dateFormatter stringFromDate:self.startTime];
NSArray *sourceArray = @[@"Both", @"Left", @"Right", @"Bottle"];
NSString *sourceString = sourceArray[self.sourceIndex];
return [[NSString alloc] initWithFormat:@"%@: Fed - %@ - %d min", startTimeString, sourceString, self.feedDuration / 60];
} else if ([self.eventType isEqualToString:@"diaperEvent"]) {
NSString *startTimeString = [dateFormatter stringFromDate:self.startTime];
NSArray *diaperArray = @[@"Wet and Dirty", @"Wet", @"Dirty"];
NSString *diaperString = diaperArray[self.diaperIndex];
return [[NSString alloc] initWithFormat:@"%@: %@ Diaper", startTimeString, diaperString];
}
return [super description];
}
最佳答案
CCIEvent中有自定义描述方法吗？默认情况下，NSObject description 将显示对象的内存位置，这正是您所看到的。您可以通过创建一些非常简单的东西来进行基本测试，例如:
- (NSString *)description
{
return [[NSString alloc] initWithFormat:@"%@", self.note];
}
它似乎仍然没有在某处加载某些内容，或者我希望您在一般使用过程中看到该问题。如果您有 CCIEvent description 方法，可以发布吗？我也很好奇 sortedAndFilteredArray。
您可以尝试通过 NSLog() 调用散布您的代码，以查看您是否在不同的点上获得了您期望的结果。当应用程序运行时，请留意 XCode 控制台以查看您获得的数据。即，在 CCIEvent.m initWithCoder 中，您可以在 if (self) { block 的末尾添加如下内容:
NSLog(@"Got %@", _note);
或者甚至在那里检查您的描述方法:
NSLog([self description]);
还要确保在您的 encodeWithCoder 方法中执行一些 NSLog。我怀疑问题是发生在保存端 - 有一些东西使事件细节无法正确保存，所以当它们被恢复时它们是空的所以在你的 cellForRowAtIndexPath 方法中它达到默认条件并且只是调用描述在 CCIEvent 上，我怀疑它可能不存在，并且正在执行显示内存位置的默认行为。如果我是对的，这表明 CCIEventStore 的 privateEvents 与您的详细信息 View 中正在编辑的事件之间存在脱节。检查头文件中的对象属性，看看是否使用复制而不是强传递某个地方的 CCIEvent。
与错误无关，但仍值得注意 - cellForRowAtIndexPath 中的项目:
cell.textLabel.text = [self.sortedAndFilteredArray[indexPath.row] description];
这些行可能与问题无关，但它们包含冗余访问器。由于您已经拥有:
CCIEvent *event = self.sortedAndFilteredArray[indexPath.row];
任何时候你想从事件中访问数据，你应该使用那个变量，所以上面的 textLabel 将是:
cell.textLabel.text = [event description];
cellForRowAtIndexPath 中还有其他几个地方可以使用类似的修改。
希望这对一些人有帮助!
关于iOS 应用程序的存档数据无法正确加载，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34242805/