Question

按下后如何保存选定的按钮状态？因此，当您在视图控制器之间切换并进入原始视图控制器时，按钮会保持按下状态，直到您再次按下它...

- (void)viewDidLoad
{
    [super viewDidLoad];

    addCheck = NO;
    favCheck = NO;
}

- (IBAction)listButton:(id)sender {

    UIImage *removeListImage = [UIImage imageNamed:@"removeList.png"];
    UIImage *addListImage = [UIImage imageNamed:@"addList.png"];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    NSMutableArray *favoriteviews = [defaults mutableArrayValueForKey:@"favorite_views_key"];

    [defaults setObject:favoriteviews forKey:@"favorite_views_key"];
    [defaults synchronize];

    if (!addCheck) {

        [addList setImage:removeListImage forState:UIControlStateNormal];

        addCheck = YES;

        [favoriteviews addObject:@"Apple"];
        [favoriteviews addObject:@"Banana"];
        [favoriteviews addObject:@"Celery"];
    }

    else if (addCheck) {
        [addList setImage:addListImage forState:UIControlStateNormal];

        addCheck = NO;

        [favoriteviews removeObject:@"Apple"];
        [favoriteviews removeObject:@"Banana"];
        [favoriteviews removeObject:@"Celery"];
    }        
}

Answer 1

对于最简单的情况，您可以为控件的两种不同状态设置图像（在本例中为按钮）。并检查每个水龙头上的状态以进行更改。例如

if(![myButton isSelected]){
    [myButton setSelected:YES];
    // Do your proceedings when the button is selected here
}
else{
   [myButton setSelected:NO];
   // Do your proceedings when the button is unselected here
}

当您在viewDidLoad中设置按钮时，只需为这两个状态设置按钮的图像

[addList setImage:addListImage forState:UIControlStateNormal];
[addList setImage:removeListImage forState:UIControlStateSelected];

或者，如果您在“界面”构建器中设置了按钮，则可以在那里为这两种状态设置这些图像。

最好添加一些逻辑来保留某种数据来设置按钮的状态。

在UIViewControllers之间导航，保留选定的按钮图像

1 个答案: