UIButton的介绍和方法的使用

介绍一个OC中的控件UIButton，顾名思义就是按钮

1. 初始化 

UIButton*btn=[UIButton buttonWithType:(UIButtonType)];

 UIButtonType是系统提供的，用来指定Button类型的枚举

    UIButtonTypeCustom

     UIButtonTypeSystem

     UIButtonTypeDetailDisclosure

     UIButtonTypeInfoLight

     UIButtonTypeInfoDark

     UIButtonTypeContactAdd

   2. 设置坐标

btn.frame=CGRectMake(0, 0, 10, 10);

3.设置编号

btn.tag=0;

  4 .设置标题

[btn setTitle:(nullable NSString *) forState:(UIControlState)];

 在这里又出现一个枚举类型<#(UIControlState)#>

     默认

     UIControlStateNormal

     高亮

     UIControlStateHighlighted  

     不可点击状态

     UIControlStateDisabled

     已被选中状态

     UIControlStateSelected

[btn setTitle:@"肯定" forState:UIControlStateNormal];
  [btn setTitle:@"取消" forState:UIControlStateHighlighted];

 5.修改字体颜色

[btn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

6 .增添点击事件

[btn addTarget:self action:@selector(selector) forControlEvents:(UIControlEvents)];

 这里出现一个枚举类型(UIControlEvents)，分别表明不一样的点击手势

    UIControlEventTouchDown

    UIControlEventTouchDownRepeat

    UIControlEventTouchDragInside

    UIControlEventTouchDragOutside

    UIControlEventTouchDragEnter

    UIControlEventTouchDragExit

    UIControlEventTouchUpInside

    UIControlEventTouchUpOutside

7.设置字体大小

btn.titleLabel.font=[UIFont systemFontOfSize:12];