//高斯模糊，毛玻璃
UIBlurEffect *blur=[UIBlurEffect effectWithStyle:UIBlurEffectStyleExtraLight];
UIVisualEffectView *effectview=[[UIVisualEffectView alloc]initWithEffect:blur];
effectview.alpha=1;//设置透明度
effectview.tag=8888;
effectview.frame=self.view.frame;
[self.view addSubview:effectview];
