UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark]; UIVisualEffectView *effectview = [[UIVisualEffectView alloc] initWithEffect:blur]; effectview.frame = CGRectMake(0,0, 320,320); [self.view addSubview:effectview];
原文：http://www.cnblogs.com/qianyindichang/p/4209488.html