边框颜色为 tintColor 的 UIButton

创建一个 UIButton 的子类，重写其方法：

- (void)drawRect:(CGRect)rect
{
    [[self layer] setCornerRadius:CORNER_RADIUS];
    [[self layer] setMasksToBounds:YES];
    [[self layer] setBorderWidth:];
    [[self layer] setBorderColor:self.tintColor.CGColor];
    [self.imageView setTintColor:self.tintColor];
}

- (void)tintColorDidChange {
    [super tintColorDidChange];
    [self setNeedsDisplay];
//    [[self layer] setBorderColor:self.tintColor.CGColor];
}