iOS去掉TabBar的顶部黑线，并添加发光的阴影

- (void)setupshadowColor{
    
    UIView * tmpView = self;
    tmpView.layer.shadowColor = [UIColor blackColor].CGColor;//设置阴影的颜色
    tmpView.layer.shadowOpacity = 0.08;//设置阴影的透明度
    tmpView.layer.shadowOffset = CGSizeMake(kAdjustRatio(0), kAdjustRatio(0));//设置阴影的偏移量,阴影的大小，x往右和y往下是正
    tmpView.layer.shadowRadius = kAdjustRatio(5);//设置阴影的圆角,//阴影的扩散范围，相当于blur radius，也是shadow的渐变距离，从外围开始，往里渐变shadowRadius距离

    
//去掉TabBar的顶部黑线    
[self setBackgroundImage:[UIImage createImageWithColor:[UIColor clearColor]]];
[self setShadowImage:[UIImage createImageWithColor:[UIColor clearColor]]];
    
}