ios - 按下按钮后标题消失

Question

我正在尝试创建一个类似“按下-按下-关闭”的按钮，例如 this one ，虽然我的代码有点不同:

UIButton* alertsButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
alertsButton.frame = CGRectMake(170, 43.5, 130, 130);
[alertsButton.titleLabel setFont:[UIFont fontWithName:@"Novecento wide" size:22]];
[alertsButton setTitle:NSLocalizedString(@"Alerts", nil) forState:UIControlStateHighlighted];
[alertsButton setTitle:NSLocalizedString(@"Alerts", nil) forState:UIControlStateNormal];
[alertsButton setTitle:NSLocalizedString(@"Alerts", nil) forState:UIControlStateSelected];
[alertsButton addTarget:self action:@selector(toggleAlerts:)forControlEvents:UIControlEventTouchUpInside];

-(void)toggleAlerts:(id)sender
{
    UIButton *button = (UIButton *)sender;

    if (button.selected) {
        button.selected = NO;
        [button setImage:[UIImage imageNamed:@"off.png"] forState:UIControlStateNormal];
        [button.titleLabel setFont:[UIFont fontWithName:@"Novecento wide" size:22]];
        NSLog(button.titleLabel.text);
    } else {
        button.selected = YES;
        [button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateNormal];
        [button.titleLabel setFont:[UIFont fontWithName:@"Novecento wide" size:22]];
        NSLog(button.titleLabel.text);
    }
}

当我按下按钮时，背景会按预期发生变化，但标签会消失，尽管它的文本显示在调试控制台中。我试过this没有结果:(

Answer 1

那是因为您的图像超出了您的标签。

而不是[button setImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateNormal];

写[button setBackgroundImage:[UIImage imageNamed:@"on.png"] forState:UIControlStateNormal];