Question

我一直在研究新的提示＆amp;为一款名为Dofus的游戏制作项目。在第一个视图中，要求用户从选择器中选择他们的类。然后他们进入下一个视图并选择他们的级别和类似的东西。然而，选择器的问题在于它从选择器中获取了错误的类。

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"background"]];

    self.classNames = @[@"Cra", @"Ecaflip", @"Eliotrope", @"Eniripsa",
                            @"Enutrof", @"Feca", @"Foggernout", @"Iop", @"Masqueraider", @"Osamodas", @"Pandawa", @"Rogue", @"Sacrier", @"Sadida", @"Sram", @"Xelor"];

}

在ViewDidLoad中我声明了我的类：

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do view setup here.
    self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"background"]];

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

    // getting an NSString
    NSString *myClass = [prefs stringForKey:@"class"];

    _textLabel.text = [NSString stringWithFormat:@"So you are a %@ huh? Pretty cool! Its a good class. Fill out the rest so we are ready to go!", myClass];
}

然后在下一个视图中，我得到这样的信息（不同的.m文件）：

{{1}}

任何人都知道这是怎么回事？提前谢谢！

Answer 1

您正在针对行标题的Picker数据源调用设置首选项，而不是选择行时的委托调用。对于加载到视图中的每一行，都会调用select * from ( select *, ( '111.045' * DEGREES( ACOS( COS( RADIANS('45.5088') ) * COS( RADIANS(lat) ) * COS( RADIANS('-73.5878' - lng) ) + SIN( RADIANS('45.5088') ) * SIN( RADIANS(lat) ) ) ) ) AS distance from `places` where lat BETWEEN 45.418746 AND 45.598854 and lng BETWEEN -73.716301 AND -73.459299 ) as d where `distance` <= 10 order by `distance` asc，此时您会设置pickerView:titleForRow:forComponent:首选项，但是，这与选择器中选择的行不对应，它对应于下一行要显示。

相反，回应 class方法，并在那里设置您的偏好（您仍然需要回复另一个来设置行标题，只是不要设置首选项。）

pickerView:didSelectRow:inComponent:

Answer 2

如果您希望用户存储所选行，则应使用UIPickerViewDelegate

中的此方法

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;

这样的事情会起作用：

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    NSString *_myClass = self.classNames[row];
    [prefs setObject:_myClass forKey:@"class"];
    [prefs synchronize];
  }
}

看一下这些链接，以便更好地了解UIPickerView的工作原理：

http://nscookbook.com/2013/01/ios-programming-recipe-7-using-the-uipickerview/

http://www.techotopia.com/index.php/An_iOS_7_UIPickerView_Example

https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIPickerView_Class/index.html#//apple_ref/doc/uid/TP40006842-CH3-SW9

Picker将随机数据保存到NSUserDefaults

2 个答案: