UIButton常见用法

//UIButton是iOS中用来响应用户点击的控件，既可以显示文字，也可以显示图片，也可以处理用户交互

//UIButton的创建，一般采用类方法来创建，不需要释放

//UIButton 也是UIControl的子类

//1、创建UIButton(一般用类方法)

//2、配置UIButton

//3、添加到父视图上面

//创建UIButton

UIButton *myButton = [UIButton buttonWithType:UIButtonTypeSystem];

//配置UIButton

//    myButton.frame = [CGRectMake(100 , 200 , 50 , 50)];

[myButton setFrame:CGRectMake(100 , 200 , 80 , 60)];

//给UIButton设置要显示的文字

[myButton setTitle:@"login" forState:UIControlStateNormal];

//设置文字大小

myButton.titleLabel.font = [UIFont systemFontOfSize:20];

//给UIButton背景色

//    myButton.backgroundColor = [UIColor orangeColor];

//给UIButton添加点击事件

[myButton addTarget:self action:@selector(myButtonAction) forControlEvents:UIControlEventTouchUpInside];

//给button添加图片

[myButton setBackgroundImage:[UIImage imageNamed:@"1.jpg"] forState:UIControlStateNormal];

[myButton setBackgroundImage:[UIImage imageNamed:@"2.jpg"] forState:UIControlStateHighlighted];

//给button添加图片，居中，而不是用al

myButton.contentMode = UIViewContentModeCenter;

//添加到父视图上面

[contentView addSubview:myButton];