UIButton设置文字居右显示

设置UIButton的文字样式，一般都会想到用设置UIButton的titleLable的textAligent属性，但是， Invalid! 下面是有效设置按钮文字居中、左、右的方法：

typedef NS_ENUM(NSInteger, UIControlContentHorizontalAlignment) {
    UIControlContentHorizontalAlignmentCenter = 0,
    UIControlContentHorizontalAlignmentRight  = 2,
    UIControlContentHorizontalAlignmentFill   = 3,
    UIControlContentHorizontalAlignmentLeading  API_AVAILABLE(ios(11.0), tvos(11.0)) = 4,
    UIControlContentHorizontalAlignmentTrailing API_AVAILABLE(ios(11.0), tvos(11.0)) = 5,
};

文字居右设置

[button setContentHorizontalAlignment:UIControlContentHorizontalAlignmentRight];