UIButton

//UIButton比UILable, UITextfield多了一个能够让用户点击并且响应的功能(点击事件)
- (void)creatButton
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
    button.backgroundColor = [UIColor brownColor];
    button.frame = CGRectMake(110, 190, 100, 40);
    //设置圆角
    button.layer.cornerRadius = 8;
    //给Button添加点击事件 让target执行action操作, 在ControlEvent发生之后 click后边的参数是: 谁调用了addTarget:action:方法, 参数就是谁, 而且参数只能有一个
    [button addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];
    //设置标题文字
    [button setTitle:@"我打" forState:UIControlStateNormal];
    //改变文字的颜色
    [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [_bgView addSubview:button];
}

- (void)click:(UIButton *)button
{
    NSLog(@"%@", button);
    NSLog(@"我打..");
}