如何使用在 NSUserDefaults 中保存值的开关显示/隐藏按钮

Question

我有名为sosSwitch 的UISwitch thas在NSUserDefaults键中保存值：MySwitch和我有名为sosBtn的UIButton。如何根据保存在 NSUserDefaults 中的开关值显示/隐藏 sosBtn？我需要把代码放在哪里？在视野中加载了吗？谢谢！

Answer 1

假设您已经拥有：

@property (retain, nonatomic) IBOutlet UIButton *sosBtn;
@property (retain, nonatomic) IBOutlet UISwitch *sosSwich;
- (IBAction)sosSwitch:(id)sender;

试试这个：

-(void)viewDidLoad
{    
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"MySwitch"])
    {
        self.sosBtn.hidden = NO;
        [self.sosSwich setOn:YES animated:YES]; 
    }
    else 
    {
        self.sosBtn.hidden = YES;
        [self.sosSwich setOn:NO animated:YES];
    }
}
- (IBAction)sosSwitch:(id)sender 
{
    UISwitch *mySosSwitch = (UISwitch *)sender;
    if (mySosSwitch.on)
    {
        self.sosBtn.hidden = NO;
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"MySwitch"];  //YES means sosBtn should be visible
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
    else 
    {
        self.sosBtn.hidden = YES;
        [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"MySwitch"];
        [[NSUserDefaults standardUserDefaults] synchronize];
    }
}