一，通过按钮的事件来设置背景色
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- (void)viewDidLoad {
[super viewDidLoad];
UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(50, 200, 100, 50)];
[button1 setTitle:@"button1" forState:UIControlStateNormal];
button1.backgroundColor = [UIColor orangeColor];
[button1 addTarget:self action:@selector(button1BackGroundHighlighted:) forControlEvents:UIControlEventTouchDown];
[button1 addTarget:self action:@selector(button1BackGroundNormal:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button1];
}// button1普通状态下的背景色- (void)button1BackGroundNormal:(UIButton *)sender
{ sender.backgroundColor = [UIColor orangeColor];
}// button1高亮状态下的背景色- (void)button1BackGroundHighlighted:(UIButton *)sender
{ sender.backgroundColor = [UIColor greenColor];
} |
二,通过把颜色转换为UIImage来作为按钮不同状态下的背景图片
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- (void)viewDidLoad {
[super viewDidLoad];
UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(170, 200, 100, 50)];
[button2 setTitle:@"button2" forState:UIControlStateNormal];
[button2 setBackgroundImage:[self imageWithColor:[UIColor redColor]] forState:UIControlStateNormal];
[button2 setBackgroundImage:[self imageWithColor:[UIColor grayColor]] forState:UIControlStateHighlighted];
[self.view addSubview:button2];
}// 颜色转换为背景图片- (UIImage *)imageWithColor:(UIColor *)color { CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [color CGColor]);
CGContextFillRect(context, rect);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
} |
三
1.首先，添加一个按钮在界面上，我们先设置好普通和高亮状态时的文字，还有圆角
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 100, 40)];
[button setTitle:@"normal" forState:UIControlStateNormal];
[button setTitle:@"highlighted" forState:UIControlStateHighlighted];
[button setBackgroundColor:[UIColor redColor]];
button.layer.cornerRadius = 10.0f;
button.layer.masksToBounds = YES;
[self.view addSubview:button];
// 添加观察者方法
[self addObserver:button];
2.添加观察者
/**
* 添加观察者
*
* @param button 需要设置的按钮
*/
- (void)addObserver:(UIButton *)button {
[button addObserver:self forKeyPath:@"highlighted" options:NSKeyValueObservingOptionNew context:nil];
}
3.接下来就是实现观察者方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context {
UIButton *button = (UIButton *)object;
if ([keyPath isEqualToString:@"highlighted"]) {
if (button.highlighted) {
[button setBackgroundColor:[UIColor blueColor]];
return;
}
[button setBackgroundColor:[UIColor redColor]];
}
}
这样我们就能在不使用图片的前提下，实现设置高亮和普通状态下的背景颜色
看下具体的效果