NSUserDefaults 设置页面不保存

Question

我想创建一个设置页面，其中 sets/gets 来自 NSUserDefaults 的滑块值（文本大小），但我的应用程序有 none 它。我没有收到任何错误，它只是不想保存。我对代码进行了注释，以帮助您更好地理解我想要做什么，但这很简单。我有一个具有字体大小的 7 级滑块，您可以简单地滑动它来确定您想要的字体大小——这就是我想要在整个应用程序中保存的值。但是每当我在导航栏上按回并再次打开设置页面时，默认大小始终是 22.

.h

@interface SettingsViewController : UIViewController

@property (strong, nonatomic) IBOutlet UISlider *sizeSlider;
@property (strong, nonatomic) IBOutlet UILabel *sampleText;

@end

.m

@interface SettingsViewController () {
    NSArray *numbers;
    NSMutableAttributedString *sampleTextString;
    int fontSize;
    NSUserDefaults *defaults;
}

@end

@implementation SettingsViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.navigationItem.title = @"Settings";

    numbers = @[@(10), @(12), @(14), @(16), @(18), @(20), @(22)];                 // Text Sizes, these number values represent each slider position
    NSInteger numberOfSteps = ((float)[numbers count]-1);                           // Slider values go from 0 to the number of values in your numbers array

    self.sizeSlider.maximumValue = numberOfSteps;                                   // As the slider moves it will continously call the -valueChanged:
    self.sizeSlider.minimumValue = 0;


    defaults = [NSUserDefaults standardUserDefaults];                                //Setting the font to be the current font saved in the system
    long textsize = [defaults integerForKey:@"fontSize"];
    NSLog(@"textsize: %ld", textsize);
    self.sizeSlider.value = textsize;                                               // Set the Slider to whatever font you had set it previously



    self.sizeSlider.continuous = YES;                                               // NO makes it call only once you let go
    [self.sizeSlider addTarget:self action:@selector(valueChanged:) forControlEvents:UIControlEventValueChanged];

    sampleTextString = [[NSMutableAttributedString alloc] initWithString:@"The Quick Brown Fox Jumps Over The Lazy Dog!"];
    self.sampleText.attributedText = sampleTextString;

    [sampleTextString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:textsize] range:NSMakeRange(0, sampleTextString.length)];

}


-(void)valueChanged:(UISlider *)sender{
    NSUInteger index = (NSUInteger)(self.sizeSlider.value + 0.5);       // round the slider position to the nearest index of the numbers array
    [self.sizeSlider setValue:index animated:NO];


    NSNumber *number = numbers[index];                                  // <-- This numeric value you want
    [sampleTextString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:[number floatValue]] range:NSMakeRange(0, sampleTextString.length)];

    [defaults setInteger:[number integerValue] forKey:@"fontSize"];         // Saving fontSize to NSUserDefaults
    [defaults synchronize];

    self.sampleText.attributedText = sampleTextString;
}
@end

Answer 1

答案来自 rmaddy - 谢谢！

我需要查看索引，而不是数组的实际值。

NSInteger indexText = [numbers indexOfObject:[NSNumber numberWithInteger:textsize]];

所以我把它放进去，它返回了我想要的滑块位置的索引。

NSUserDefaults 设置页面不保存

NSUserDefaults Settings Page Not Saving

ios

nsuserdefaults

uislider