-(UIView*)bgView{
if(!_bgView) {
_bgView=[[UIViewalloc]init];
_bgView.backgroundColor = [UIColor whiteColor];
_bgView.layer.shadowColor = [UIColor colorWithRed:51/255.0 green:51/255.0 blue:51/255.0 alpha:0.1].CGColor;
_bgView.layer.shadowOffset = CGSizeMake(0, 1);
_bgView.layer.shadowOpacity = 1;
_bgView.layer.shadowRadius = 8;
_bgView.layer.cornerRadius =4;
///maskLayer带有mask属性, 并嵌入到shaowLayer
CALayer*maskLayer = [CALayerlayer];
maskLayer.frame=_bgView.layer.bounds;
maskLayer.masksToBounds=YES;
[_bgView.layeraddSublayer:maskLayer];
}
return _bgView;
}
