Question

我收到错误

- [NSDictionary initWithObjects：forKeys：]：对象的数量（0）与键的数量不同（2）'

这是保存plist的代码。

    @interface setting : UIViewController{
    UIDatePicker *datePicker;
    IBOutlet UILabel * morningtime;
    UIDatePicker *afternoonpicker;
    NSString*morningtime1;
    NSString*afternoontime1;
     IBOutlet UILabel *afternoontime;
}
@property (nonatomic,retain) IBOutlet UIDatePicker *datePicker;
@property (strong, nonatomic) IBOutlet UIDatePicker *afternoonpicker;

@property (nonatomic, retain) IBOutlet NSString *morningtime1;

@property (nonatomic, retain) IBOutlet NSString *afternoontime1;
@property (nonatomic, retain) IBOutlet UILabel *morningtime;

@property (nonatomic, retain) IBOutlet UILabel *afternoontime;
@property (weak, nonatomic) IBOutlet UIButton *morning;




- (IBAction)savetext:(id)sender {
    NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
    // get documents path
    NSString *documentsPath = [paths objectAtIndex:0];
    // get the path to our Data/plist file
    NSString *plistPath = [documentsPath stringByAppendingPathComponent:@"Data.plist"];

    self.morningtime1 = morningtime.text;
    self.afternoontime1 = afternoontime.text;
    NSDictionary *plistDict = [NSDictionary dictionaryWithObjects: [NSArray arrayWithObjects: morningtime1, afternoontime1, nil] forKeys:[NSArray arrayWithObjects: @"Morning", @"Afternoon", nil]];

    NSString *error = nil;
    // create NSData from dictionary
    NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];

    // check is plistData exists
    if(plistData)
    {
        // write plistData to our Data.plist file
        [plistData writeToFile:plistPath atomically:YES];
    }
    else
    {
        NSLog(@"Error in saveData: %@", error);
    }
}

Answer 1

morningtime1几乎肯定是nil，过早地结束了数组列表。

如果你在这里使用了新的数组文字语法：

@[morningtime1, afternoontime1];

你会崩溃，因为将nil分配给NSArray元素是违法的。

Answer 2

这一行：

NSDictionary *plistDict = [NSDictionary dictionaryWithObjects: [NSArray arrayWithObjects: morningtime1, afternoontime1, nil] forKeys:[NSArray arrayWithObjects: @"Morning", @"Afternoon", nil]];

应该是：

NSDictionary *plistDict = [NSDictionary dictionaryWithObjects: [NSArray arrayWithObjects: self.morningtime1, self.afternoontime1, nil] forKeys:[NSArray arrayWithObjects: @"Morning", @"Afternoon", nil]];

换句话说，引用属性，而不是ivars。如你所知，永远不会设置morningtime1 ivar（你设置实际设置生成的名为_morningtime1的ivar的属性。

旁注：

删除属性的任何明确的ivars和@synthesize行。这样可以避免这种混淆。

- [NSDictionary initWithObjects：forKeys：]：对象计数（0）与键计数不同（2）

2 个答案: