ios UIButton設置高亮狀態下的背景色
阿新 • • 發佈：2018-03-07
背景圖 nil 效果 equal ext ex18 syntax keyword gef
一，通過按鈕的事件來設置背景色
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 |
- (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普通狀態下的背景色
- (void)button1BackGroundNormal:(UIButton *)sender
{
sender.backgroundColor = [UIColor orangeColor];
}
// button1高亮狀態下的背景色
- (void)button1BackGroundHighlighted:(UIButton *)sender
{
sender.backgroundColor = [UIColor greenColor];
}
|
二,通過把顏色轉換為UIImage來作為按鈕不同狀態下的背景圖片
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 |
- (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];
}
// 顏色轉換為背景圖片
- (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，添加一個按鈕在界面上，我們先設置好普通和高亮狀態時的文字，還有圓角
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];
// 添加觀察者方法
[self addObserver:button];
2.添加觀察者
/**
* 添加觀察者
*
* @param button 需要設置的按鈕
*/
- (void)addObserver:(UIButton *)button {
[button addObserver:self forKeyPath:@"highlighted" options:NSKeyValueObservingOptionNew context:nil];
}
3.接下來就是實現觀察者方法
- (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]];
}
}
這樣我們就能在不使用圖片的前提下，實現設置高亮和普通狀態下的背景顏色
看下具體的效果
ios UIButton設置高亮狀態下的背景色