UISwitch-offTintColor

/// 设置UISwitch 未选中颜色, 支持缩放后正确展示
/// @param sw sw
/// @param color 关闭状态颜色
- (void)kSetSwitchOffTintColor:(UISwitch *)sw offTintColor:(UIColor *)color{
    NSArray * arr1 = sw.subviews;
    if (arr1.count > 0) {
        UIView * view1 = arr1[0];
        NSArray * arr2 = view1.subviews;
        if (arr2.count > 0) {
            UIView * view2 = arr2.firstObject;
            view2.backgroundColor = color;
        }
    }
}