Question

我正在尝试将一个包含5个数据对象的自定义对象的可变数组写入磁盘。但是，使用unarchiver总是使我的数组变为null，我无法弄清楚原因。这是方法:( self.toDoItems是在这个类中定义的NSMutableArray）

- (void)viewDidLoad {
    [super viewDidLoad];
    self.toDoItems = [[NSMutableArray alloc] init];
    NSLog(@"toDOitems on load = %@",self.toDoItems);

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *appFile = [documentsDirectory stringByAppendingPathComponent:@"deliveries.txt"];

    self.toDoItems = [NSKeyedUnarchiver unarchiveObjectWithFile:appFile];
    NSLog(@"toDOitems after unarchive = %@",self.toDoItems);

    [self loadInitialData1];

    //load array here
}

这是输出：

2015-06-28 17:15:07.778 ToDoList[13493:645560] toDOitems on load = (
)
2015-06-28 17:15:07.780 ToDoList[13493:645560] toDOitems after unarchive =     (null)
2015-06-28 17:15:07.780 ToDoList[13493:645560] toDOitems = (null)
2015-06-28 17:18:42.498 ToDoList[13493:647529]

这是NSCoding的实现：

#import "ToDoItem.h"

@implementation ToDoItem


-(void)encodeWithCoder:(NSCoder *)encoder{
    [encoder encodeObject:self.total forKey:@"total"];
    [encoder encodeObject:self.tip forKey:@"tip"];
    [encoder encodeObject:self.percentage forKey:@"percentage"];
    [encoder encodeBool:self.completed forKey:@"completed"];
    [encoder encodeBool:self.isCreditCard forKey:@"isCreditCard"];

}

- (id)initWithCoder:(NSCoder *)decoder {
    if (self = [super init]) {
        self.total = [decoder decodeObjectForKey:@"total"];
        self.tip = [decoder decodeObjectForKey:@"tip"];
        self.percentage = [decoder decodeObjectForKey:@"percentage"];
        self.completed = [decoder decodeBoolForKey:@"completed"];
        self.isCreditCard = [decoder decodeBoolForKey:@"isCreditCard"];
    }
    return self;
}

@end

NSkeyedUnarchiver使可变数组变为null

0 个答案: