//放置按钮
//登录
_loginButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
_loginButton.frame = CGRectMake(20, 300, 280, 35);
_loginButton.backgroundColor = [UIColor blueColor];
[_loginButton setTitle:@"登录" forState:UIControlStateNormal];
//自定义 圆角按钮
[_loginButton.layer setMasksToBounds:YES];
[_loginButton.layer setCornerRadius:4.0];
//[_loginButton.layer setBorderWidth:1.0];
[self addSubview:_loginButton];