如何保存/检索 UIButton 状态？

Question

这是我的第一个问题！

我将 UIButton 与 UISwitch 功能一起使用，并且我想保存/检索 UIButton 的状态。 请帮忙！

已解决！

感谢 Kalle 和 aBitObvious！

我使用的代码：

.h

@interface RetinaViewController : UIViewController {
IBOutlet UIButton *mybutton;

}

-(IBAction) toggleUIButtonImage:(id)sender;


@end

.m

@implementation RetinaViewController

-(IBAction) toggleUIButtonImage:(id)sender{
NSString *value = @"ON";
NSUserDefaults *userPreferences = [NSUserDefaults standardUserDefaults];
UIImage *unselectedImage = [UIImage imageNamed: @"OFFa.png"];
UIImage *selectedImage = [UIImage imageNamed:@"ONa.png"];
    if ([sender isSelected]) {
    [sender setImage:unselectedImage forState:UIControlStateNormal];
    [sender setSelected:NO];
        value = @"OFF";
        [userPreferences setObject:value forKey:@"stateOfButton"];
}else {
    [sender setImage:selectedImage forState:UIControlStateSelected];
    [sender setSelected:YES];
    value = @"ON";
    [userPreferences setObject:value forKey:@"stateOfButton"];
}

[userPreferences synchronize];
}



- (void)viewDidLoad {

NSString *value = [[NSUserDefaults standardUserDefaults]  stringForKey:@"stateOfButton"];

// If value is nil - disable the switch
if (value == nil) { 
    mybutton.selected = NO;
}
// If value is equal to ON
else if ([value compare:@"ON"] == NSOrderedSame) {

    //NSLog(@"the switch is on");

    // Set the switch to ON
    mybutton.selected = YES;

} else {

    //NSLog(@"the switch is off");

    // Set the switch to OFF
    mybutton.selected = NO;
}


    [super viewDidLoad];
}

Answer 1

在视图控制器的 viewDidLoad 中，输入如下内容：

NSUserDefaults *userPreferences = [NSUserDefaults standardUserDefaults];
NSString *stateOfButton = [userPreferences stringForKey:@"stateOfButton"];
if ([stateOfButton isEqualToString:@"ON"])
{
    //set button state to "selected"
}
else
{
    //set button state to "not selected"
}